Combining Philosophers

All the ideas for Anaxarchus, Thomas Hobbes and Theodore Sider

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226 ideas

1. Philosophy / C. History of Philosophy / 4. Later European Philosophy / b. Seventeenth century philosophy
Hobbes created English-language philosophy [Hobbes, by Tuck]
     Full Idea: Hobbes created English-language philosophy.
     From: report of Thomas Hobbes (The Elements of Law [1640]) by Richard Tuck - Hobbes Pref
     A reaction: Tuck mentions Hooker as a predecessor in jurisprudence. Otherwise, an impressive label.
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Maybe what distinguishes philosophy from science is its pursuit of necessary truths [Sider]
     Full Idea: According to one tradition, necessary truth demarcates philosophical from empirical inquiry. Science identifies contingent aspects of the world, whereas philosophical inquiry reveals the essential nature of its objects.
     From: Theodore Sider (Reductive Theories of Modality [2003], 1)
     A reaction: I don't think there is a clear demarcation, and I would think that lots of generalizations about contingent truths are in philosophical territory, but I quite like this idea - even if it does make scientists laugh at philosophers.
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Definitions are the first step in philosophy [Hobbes]
     Full Idea: In beginning philosophy, the first beginning is from definitions.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.15)
     A reaction: Note that he doesn't say that definitions are the aim of philosophy, as some analysts might think.
1. Philosophy / D. Nature of Philosophy / 8. Humour
Laughter is a sudden glory in realising the infirmity of others, or our own formerly [Hobbes]
     Full Idea: The passion of laughter is nothing else but sudden glory arising from some sudden conception of some eminency in ourselves, by comparison with the infirmity of others, or with our own formerly.
     From: Thomas Hobbes (Human Nature [1640], Ch.IX.13)
     A reaction: Laughter tends to involve something unusual. We don't just burst out with a glory of vanity whenever we meet some inferiority in another person.
1. Philosophy / E. Nature of Metaphysics / 2. Possibility of Metaphysics
Metaphysical enquiry can survive if its conclusions are tentative [Sider]
     Full Idea: Metaphysical enquiry can survive if we are willing to live with highly tentative conclusions.
     From: Theodore Sider (Four Dimensionalism [2001], Intro)
     A reaction: Nice. Nothing alienates the rather literal scientific sort of mind quicker that bold, dogmatic and even arrogant assertions about metaphysics. But to entirely close down metaphysical speculation for that reason is absurd.
Your metaphysics is 'cheating' if your ontology won't support the beliefs you accept [Sider]
     Full Idea: Ontological 'cheaters' are those ne'er-do-well metaphysicians (such as presentists, phenomenalists, or solipsists) who refuse to countenance a sufficiently robust conception of the fundamental to underwrite the truths they accept.
     From: Theodore Sider (Writing the Book of the World [2011], 08.4)
     A reaction: Presentists are placed in rather insalubrious company here, The notion of 'cheaters' is nice, and I associate it with Australian philosophy, and the reason that was admired by David Lewis.
1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
Metaphysics is not about what exists or is true or essential; it is about the structure of reality [Sider]
     Full Idea: Metaphysics, at bottom, is about the fundamental structure of reality. Not about what's necessarily true. Not about what properties are essential. Not about conceptual analysis. Not about what there is. Structure.
     From: Theodore Sider (Writing the Book of the World [2011], 01)
     A reaction: The opening words of his book. I take them to be absolutely correct, and to articulate the new orthodoxy about metaphysics which has emerged since about 1995. He expands this as being about patterns, categories and joints.
Extreme doubts about metaphysics also threaten to undermine the science of unobservables [Sider]
     Full Idea: The most extreme critics of metaphysics base their critique on sweeping views about language (logical positivism), or knowledge (empiricism), ...but this notoriously threatens the science of unobservables as much as it threatens metaphysics.
     From: Theodore Sider (Writing the Book of the World [2011], 05.1)
     A reaction: These criticisms also threaten speculative physics (even about what is possibly observable).
1. Philosophy / E. Nature of Metaphysics / 6. Metaphysics as Conceptual
It seems unlikely that the way we speak will give insights into the universe [Sider]
     Full Idea: It has always seemed odd that insight into the fundamental workings of the universe should be gained by reflection on how we think and speak.
     From: Theodore Sider (Writing the Book of the World [2011], 07.8)
     A reaction: A nice expression of what should by now be obvious to all philosophers - that analysis of language is not going to reveal very much. It is merely clearing the undergrowth so that we can go somewhere.
1. Philosophy / F. Analytic Philosophy / 2. Analysis by Division
Resolve a complex into simple elements, then reconstruct the complex by using them [Hobbes, by MacIntyre]
     Full Idea: Hobbes took his method from Galileo, of resolving any complex situation into its logically primitive, simple elements and then using the simple elements to show how the complex situation could be reconstructed.
     From: report of Thomas Hobbes (Leviathan [1651]) by Alasdair MacIntyre - A Short History of Ethics Ch.10
     A reaction: Reverse engineering of reality. This idea, wherever it comes from, strikes me as the key to the advance of human understanding. No one has yet improved on it as a method, in science or philosophy. Reconstruction needs the mechanism.
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
Conceptual analysts trust particular intuitions much more than general ones [Sider]
     Full Idea: Conceptual analysts generally regard intuitive judgements about particular cases as being far more diagnostic than intuitive judgements about general principles.
     From: Theodore Sider (Writing the Book of the World [2011], 02.4 n7)
     A reaction: Since I take the aim to be the building up an accurate picture about general truths, it would be daft to just leap to our intuitions about those general truths. Equally you can't cut intuition out of the picture (pace Ladyman).
2. Reason / D. Definition / 2. Aims of Definition
Definitions of things that are caused must express their manner of generation [Hobbes]
     Full Idea: Definitions of things which may be understood to have some cause, must consist of such names as express the cause or manner of their generation, as when we define a circle to be a figure made by the circumduction of a straight line in a plane etc.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.13)
     A reaction: His account of the circle is based on its mode of construction, which is the preferred account of Euclid, rather than a statement of its pure nature.
2. Reason / D. Definition / 5. Genus and Differentia
Definition is resolution of names into successive genera, and finally the difference [Hobbes]
     Full Idea: The definition is nothing but a resolution of the name into its most universal parts; ...definitions of this kind always consist of genus and difference; the former names being all, till the last, general; and the last of all, difference.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.14)
     A reaction: This is basically the scholastic Aristotelian view of definition. Note that Hobbes explicitly denies that the last step of the definition is general in character.
2. Reason / D. Definition / 8. Impredicative Definition
A defined name should not appear in the definition [Hobbes]
     Full Idea: A defined name ought not to be repeated in the definition. ...No total can be part of itself.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.15)
2. Reason / D. Definition / 13. Against Definition
Philosophical concepts are rarely defined, and are not understood by means of definitions [Sider]
     Full Idea: Philosophical concepts of interest are rarely reductively defined; still more rarely does our understanding of such concepts rest on definitions. ...(We generally understand concepts to the extent that we know what role they play in thinking).
     From: Theodore Sider (Writing the Book of the World [2011], 02.1)
     A reaction: I'm not sure that I agree with this. I suspect that Sider has the notion of definition in mind that is influenced by lexicography. Aristotle's concept of definition I take to be lengthy and expansive, and that is very relevant to philosophy.
It seems possible for a correct definition to be factually incorrect, as in defining 'contact' [Sider]
     Full Idea: Arguably, 'there is absolutely no space between two objects in contact' is false, but definitional of 'contact'. ...We need a word for true definitional sentences. I propose: 'analytic'.
     From: Theodore Sider (Writing the Book of the World [2011], 09.8)
2. Reason / F. Fallacies / 3. Question Begging
'Petitio principii' is reusing the idea to be defined, in disguised words [Hobbes]
     Full Idea: 'Petitio principii' is when the conclusion to be proved is disguised in other words, and put for the definition or principle from whence it is to be demonstrated.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.18)
3. Truth / A. Truth Problems / 3. Value of Truth
We don't care about plain truth, but truth in joint-carving terms [Sider]
     Full Idea: What we care about is truth in joint-carving terms, not just truth.
     From: Theodore Sider (Writing the Book of the World [2011], 04.5)
     A reaction: The thought is that it matters what conceptual scheme is used to express the truth (the 'ideology'). Truths can be true but uninformative or unexplanatory.
3. Truth / B. Truthmakers / 5. What Makes Truths / b. Objects make truths
Orthodox truthmaker theories make entities fundamental, but that is poor for explanation [Sider]
     Full Idea: According to the entrenched truthmaker theorist, the fundamental facts consist just of facts citing the existence of entities. It's hard to see how all the complexity we experience could possibly be explained from that sparse basis.
     From: Theodore Sider (Writing the Book of the World [2011], 08.5)
     A reaction: This may be the 'entrenched' truthmaker view, but it is not clear why there could not be more complicated fundamental truthmakers, with structure as well as entities. And powers.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
'Theorems' are formulas provable from no premises at all [Sider]
     Full Idea: Formulas provable from no premises at all are often called 'theorems'.
     From: Theodore Sider (Logic for Philosophy [2010], 2.6)
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Truth tables assume truth functionality, and are just pictures of truth functions [Sider]
     Full Idea: The method of truth tables assumes truth functionality. Truth tables are just pictures of truth functions.
     From: Theodore Sider (Logic for Philosophy [2010], 6.3)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
Intuitively, deontic accessibility seems not to be reflexive, but to be serial [Sider]
     Full Idea: Deontic accessibility seems not to be reflexive (that it ought to be true doesn't make it true). One could argue that it is serial (that there is always a world where something is acceptable).
     From: Theodore Sider (Logic for Philosophy [2010], 6.3.1)
In D we add that 'what is necessary is possible'; then tautologies are possible, and contradictions not necessary [Sider]
     Full Idea: In D we add to K a new axiom saying that 'what's necessary is possible' (□φ→◊φ), ..and it can then be proved that tautologies are possible and contradictions are not necessary.
     From: Theodore Sider (Logic for Philosophy [2010], 6.4.2)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
System B introduces iterated modalities [Sider]
     Full Idea: With system B we begin to be able to say something about iterated modalities. ..S4 then takes a different stand on the iterated modalities, and neither is an extension of the other.
     From: Theodore Sider (Logic for Philosophy [2010], 6.4.4)
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
S5 is the strongest system, since it has the most valid formulas, because it is easy to be S5-valid [Sider]
     Full Idea: S5 is the strongest system, since it has the most valid formulas. That's because it has the fewest models; it's easy to be S5-valid since there are so few potentially falsifying models. K is the weakest system, for opposite reasons.
     From: Theodore Sider (Logic for Philosophy [2010], 6.3.2)
     A reaction: Interestingly, the orthodox view is that S5 is the correct logic for metaphysics, but it sounds a bit lax. Compare Idea 13707.
4. Formal Logic / D. Modal Logic ML / 5. Epistemic Logic
Epistemic accessibility is reflexive, and allows positive and negative introspection (KK and K¬K) [Sider]
     Full Idea: Epistemic accessibility should be required to be reflexive (allowing Kφ→φ). S4 allows the 'KK principle', or 'positive introspection' (Kφ→KKφ), and S5 allows 'negative introspection' (¬Kφ→K¬Kφ).
     From: Theodore Sider (Logic for Philosophy [2010], 7.2)
4. Formal Logic / D. Modal Logic ML / 6. Temporal Logic
We can treat modal worlds as different times [Sider]
     Full Idea: We can think of the worlds of modal logic as being times, rather than 'possible' worlds.
     From: Theodore Sider (Logic for Philosophy [2010], 7.3.3)
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Converse Barcan Formula: □∀αφ→∀α□φ [Sider]
     Full Idea: The Converse Barcan Formula reads □∀αφ→∀α□φ (or an equivalent using ◊).
     From: Theodore Sider (Logic for Philosophy [2010], 9.5.2)
     A reaction: I would read that as 'if all the αs happen to be φ, then αs have to be φ'. Put like that, I would have thought that it was obviously false. Sider points out that some new object could turn up which isn't φ.
The Barcan Formula ∀x□Fx→□∀xFx may be a defect in modal logic [Sider]
     Full Idea: The Barcan Formula ∀x□Fx→□∀xFx is often regarded as a defect of Simple Quantified Modal Logic, though this most clearly seen in its equivalent form ◊∃xFx→∃x◊Fx.
     From: Theodore Sider (Logic for Philosophy [2010], 9.5.2)
     A reaction: [See Idea 13719 for an explanation why it might be a defect] I translate the first one as 'if xs must be F, then they are always F', and the second one as 'for x to be possibly F, there must exist an x which is possibly F'. Modality needs existence.
System B is needed to prove the Barcan Formula [Sider]
     Full Idea: The proof of the Barcan Formula require System B.
     From: Theodore Sider (Logic for Philosophy [2010], 9.7)
The Barcan schema implies if X might have fathered something, there is something X might have fathered [Sider]
     Full Idea: If we accept the Barcan and converse Barcan schemas, this leads to surprising ontological consequences. Wittgenstein might have fathered something, so, by the Barcan schema, there is something that Wittgenstein might have fathered.
     From: Theodore Sider (Writing the Book of the World [2011], 11.9)
     A reaction: [He cites Tim Williamson for this line of thought] I was liking the Barcan picture, by now I am backing away fast. They cannot be serious!
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
You can employ intuitionist logic without intuitionism about mathematics [Sider]
     Full Idea: Not everyone who employs intuitionistic logic is an intuitionist about mathematics.
     From: Theodore Sider (Logic for Philosophy [2010], 7.4.1)
     A reaction: This seems worthy of note, since it may be tempting to reject the logic because of the implausibility of the philosophy of mathematics. I must take intuitionist logic more seriously.
4. Formal Logic / G. Formal Mereology / 1. Mereology
'Gunk' is an object in which proper parts all endlessly have further proper parts [Sider]
     Full Idea: An object is 'gunky' if each of its parts has further proper parts; thus gunk involves infinite descent in the part-whole relation.
     From: Theodore Sider (Writing the Book of the World [2011], 07.11.2)
4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology
A part of a part is a part of a whole [Hobbes]
     Full Idea: A part of a part is a part of a whole.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.07.09)
Which should be primitive in mereology - part, or overlap? [Sider]
     Full Idea: Should our fundamental theory of part and whole take 'part' or 'overlap' as primitive?
     From: Theodore Sider (Writing the Book of the World [2011], 02.3)
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
There is a real issue over what is the 'correct' logic [Sider]
     Full Idea: Certain debates over the 'correct' logic are genuine, and not linguistic or conceptual.
     From: Theodore Sider (Writing the Book of the World [2011], 01.3)
     A reaction: It is rather hard to give arguments in favour of this view, but I am pleased to have the authority of Sider with me.
'It is raining' and 'it is not raining' can't be legislated, so we can't legislate 'p or ¬p' [Sider]
     Full Idea: I cannot legislate-true 'It is raining' and I cannot legislate true 'It is not raining', so if I cannot legislate either true then I cannot legislate-true the disjunction 'it is raining or it is not raining'.
     From: Theodore Sider (Writing the Book of the World [2011], 06.5)
     A reaction: This strikes me as a very simple and very persuasive argument against the idea that logic is a mere convention. I take disjunction to be an abstract summary of how the world works. Sider seems sympathetic.
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is good for mathematics and science, but less good for natural language [Sider]
     Full Idea: Despite its brilliant success in mathematics and fundamental science, classical logic applies uneasily to natural language.
     From: Theodore Sider (Writing the Book of the World [2011], 10.6)
     A reaction: He gives examples of the conditional, and debates over the meaning of 'and', 'or' and 'not', and also names and quantifiers. Many modern philosophical problems result from this conflict.
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
The most popular account of logical consequence is the semantic or model-theoretic one [Sider]
     Full Idea: On the question of the nature of genuine logical consequence, ...the most popular answer is the semantic, or model-theoretic one.
     From: Theodore Sider (Logic for Philosophy [2010], 1.5)
     A reaction: Reading the literature, one might be tempted to think that this is the only account that anyone takes seriously. Substitutional semantics seems an interesting alternative.
Maybe logical consequence is more a matter of provability than of truth-preservation [Sider]
     Full Idea: Another answer to the question about the nature of logical consequence is a proof-theoretic one, according to which it is more a matter of provability than of truth-preservation.
     From: Theodore Sider (Logic for Philosophy [2010], 1.5)
     A reaction: I don't like this, and prefer the model-theoretic or substitutional accounts. Whether you can prove that something is a logical consequence seems to me entirely separate from whether you can see that it is so. Gödel seems to agree.
Maybe logical consequence is impossibility of the premises being true and the consequent false [Sider]
     Full Idea: The 'modal' account of logical consequence is that it is not possible for the premises to be true and the consequent false (under some suitable notion of possibility).
     From: Theodore Sider (Logic for Philosophy [2010], 1.5)
     A reaction: Sider gives a nice summary of five views of logical consequence, to which Shapiro adds substitutional semantics.
Maybe logical consequence is a primitive notion [Sider]
     Full Idea: There is a 'primitivist' account, according to which logical consequence is a primitive notion.
     From: Theodore Sider (Logic for Philosophy [2010], 1.5)
     A reaction: While sympathetic to substitutional views (Idea 13674), the suggestion here pushes me towards thinking that truth must be at the root of it. The trouble, though, is that a falsehood can be a good logical consequence of other falsehoods.
Modal accounts of logical consequence are simple necessity, or essential use of logical words [Sider]
     Full Idea: The simplest modal account is that logical consequence is just necessary consequence; another modal account says that logical consequences are modal consequences that involve only logical words essentially.
     From: Theodore Sider (Writing the Book of the World [2011], 12.3)
     A reaction: [He cites Quine's 'Carnap and Logical Truth' for the second idea] Sider is asserting that Humeans like him dislike modality, and hence need a nonmodal account of logical consequence.
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
A 'theorem' is an axiom, or the last line of a legitimate proof [Sider]
     Full Idea: A 'theorem' is defined as the last line of a proof in which each line is either an axiom or follows from earlier lines by a rule.
     From: Theodore Sider (Logic for Philosophy [2010], 9.7)
     A reaction: In other words, theorems are the axioms and their implications.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Define logical constants by role in proofs, or as fixed in meaning, or as topic-neutral [Sider]
     Full Idea: Some say that logical constants are those expressions that are defined by their proof-theoretic roles, others that they are the expressions whose semantic values are permutation-invariant, and still others that they are the topic-neutral expressions.
     From: Theodore Sider (Writing the Book of the World [2011], 10.3)
     A reaction: [He cites MacFarlane 2005 as giving a survey of this]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
When a variable is 'free' of the quantifier, the result seems incapable of truth or falsity [Sider]
     Full Idea: When a variable is not combined with a quantifier (and so is 'free'), the result is, intuitively, semantically incomplete, and incapable of truth or falsity.
     From: Theodore Sider (Logic for Philosophy [2010], 4.2)
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
A 'total' function must always produce an output for a given domain [Sider]
     Full Idea: Calling a function a 'total' function 'over D' means that the function must have a well-defined output (which is a member of D) whenever it is given as inputs any n members of D.
     From: Theodore Sider (Logic for Philosophy [2010], 5.2)
5. Theory of Logic / F. Referring in Logic / 3. Property (λ-) Abstraction
λ can treat 'is cold and hungry' as a single predicate [Sider]
     Full Idea: We might prefer λx(Fx∧Gx)(a) as the symbolization of 'John is cold and hungry', since it treats 'is cold and hungry' as a single predicate.
     From: Theodore Sider (Logic for Philosophy [2010], 5.5)
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Good axioms should be indisputable logical truths [Sider]
     Full Idea: Since they are the foundations on which a proof rests, the axioms in a good axiomatic system ought to represent indisputable logical truths.
     From: Theodore Sider (Logic for Philosophy [2010], 2.6)
No assumptions in axiomatic proofs, so no conditional proof or reductio [Sider]
     Full Idea: Axiomatic systems do not allow reasoning with assumptions, and therefore do not allow conditional proof or reductio ad absurdum.
     From: Theodore Sider (Logic for Philosophy [2010], 2.6)
     A reaction: Since these are two of the most basic techniques of proof which I have learned (in Lemmon), I shall avoid axiomatic proof systems at all costs, despites their foundational and Ockhamist appeal.
5. Theory of Logic / H. Proof Systems / 3. Proof from Assumptions
Proof by induction 'on the length of the formula' deconstructs a formula into its accepted atoms [Sider]
     Full Idea: The style of proof called 'induction on formula construction' (or 'on the number of connectives', or 'on the length of the formula') rest on the fact that all formulas are built up from atomic formulas according to strict rules.
     From: Theodore Sider (Logic for Philosophy [2010], 2.7)
     A reaction: Hence the proof deconstructs the formula, and takes it back to a set of atomic formulas have already been established.
Induction has a 'base case', then an 'inductive hypothesis', and then the 'inductive step' [Sider]
     Full Idea: A proof by induction starts with a 'base case', usually that an atomic formula has some property. It then assumes an 'inductive hypothesis', that the property is true up to a certain case. The 'inductive step' then says it will be true for the next case.
     From: Theodore Sider (Logic for Philosophy [2010], 2.7)
     A reaction: [compressed]
5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
'Tonk' is supposed to follow the elimination and introduction rules, but it can't be so interpreted [Sider]
     Full Idea: 'Tonk' is stipulated by Prior to stand for a meaning that obeys the elimination and introduction rules; but there simply is no such meaning; 'tonk' cannot be interpreted so as to obey the rules.
     From: Theodore Sider (Writing the Book of the World [2011], 06.5)
     A reaction: 'Tonk' thus seems to present a problem for so-called 'natural' deduction, if the natural deduction consists of nothing more than obey elimination and introduction rules.
Natural deduction helpfully allows reasoning with assumptions [Sider]
     Full Idea: The method of natural deduction is popular in introductory textbooks since it allows reasoning with assumptions.
     From: Theodore Sider (Logic for Philosophy [2010], 2.5)
     A reaction: Reasoning with assumptions is generally easier, rather than being narrowly confined to a few tricky axioms, You gradually show that an inference holds whatever the assumption was, and so end up with the same result.
5. Theory of Logic / H. Proof Systems / 6. Sequent Calculi
We can build proofs just from conclusions, rather than from plain formulae [Sider]
     Full Idea: We can construct proofs not out of well-formed formulae ('wffs'), but out of sequents, which are some premises followed by their logical consequence. We explicitly keep track of the assumptions upon which the conclusion depends.
     From: Theodore Sider (Logic for Philosophy [2010], 2.5.1)
     A reaction: He says the method of sequents was invented by Gerhard Gentzen (the great nazi logician) in 1935. The typical starting sequents are the introduction and elimination rules. E.J. Lemmon's book, used in this database, is an example.
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
Valuations in PC assign truth values to formulas relative to variable assignments [Sider]
     Full Idea: A valuation function in predicate logic will assign truth values to formulas relative to variable assignments.
     From: Theodore Sider (Logic for Philosophy [2010], 4.2)
     A reaction: Sider observes that this is a 'double' relativisation (due to Tarski), since propositional logic truth was already relative to an interpretation. Now we are relative to variable assignments as well.
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
The semantical notion of a logical truth is validity, being true in all interpretations [Sider]
     Full Idea: The semantical notion of a logical truth is that of a valid formula, which is true in all interpretations. In propositional logic they are 'tautologies'.
     From: Theodore Sider (Logic for Philosophy [2010], 2.3)
     A reaction: This implies that there is a proof-theoretic account of logical truth as well. Intuitively a logical truth is a sequent which holds no matter which subject matter it refers to, so the semantic view sounds OK.
It is hard to say which are the logical truths in modal logic, especially for iterated modal operators [Sider]
     Full Idea: It isn't clear which formulas of modal propositional logic are logical truths, ...especially for sentences that contain iterations of modal operators. Is □P→□□P a logical truth? It's hard to say.
     From: Theodore Sider (Logic for Philosophy [2010], 6.3)
     A reaction: The result, of course, is that there are numerous 'systems' for modal logic, so that you can choose the one that gives you the logical truths you want. His example is valid in S4 and S5, but not in the others.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
In model theory, first define truth, then validity as truth in all models, and consequence as truth-preservation [Sider]
     Full Idea: In model theory one normally defines some notion of truth in a model, and then uses it to define validity as truth in all models, and semantic consequence as the preservation of truth in models.
     From: Theodore Sider (Logic for Philosophy [2010], 10.1)
5. Theory of Logic / K. Features of Logics / 4. Completeness
In a complete logic you can avoid axiomatic proofs, by using models to show consequences [Sider]
     Full Idea: You can establish facts of the form Γ|-φ while avoiding the agonies of axiomatic proofs by reasoning directly about models to conclusions about semantic consequence, and then citing completeness.
     From: Theodore Sider (Logic for Philosophy [2010], 4.5)
     A reaction: You cite completeness by saying that anything which you have shown to be a semantic consequence must therefore be provable (in some way).
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness surprisingly says that no contradictions can emerge when the set goes infinite [Sider]
     Full Idea: Compactness is intuitively surprising, ..because one might have thought there could be some contradiction latent within some infinite set, preventing it from being satisfiable, only discovered when you consider the whole set. But this can't happen.
     From: Theodore Sider (Logic for Philosophy [2010], 4.5)
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
If we just say one, one, one, one, we don't know where we have got to [Hobbes]
     Full Idea: By saying one, one, one, one, and so forward, we know not what number we are at beyond two or three.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.12.05)
     A reaction: This makes ordinals sound like meta-numbers.
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
A single second-order sentence validates all of arithmetic - but this can't be proved axiomatically [Sider]
     Full Idea: A single second-order sentence has second-order semantic consequences which are all and only the truths of arithmetic, but this is cold comfort because of incompleteness; no axiomatic system draws out the consequences of this axiom.
     From: Theodore Sider (Logic for Philosophy [2010], 5.4.3)
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
Only supernatural means could annihilate anything once it had being [Hobbes]
     Full Idea: A being cannot naturally go out of existence. For even if a ship or a plank ceases to be a ship or a plank, it never naturally ceases to be a being. For a being, unless it is annihilated, does not cease to be a being. To annihilate is a supernatural task.
     From: Thomas Hobbes (De Mundo (On the World) [1642], 12.5)
     A reaction: This idea was becoming an orthodoxy in Hobbes's time, and leads to the various conservation laws in physics.
7. Existence / B. Change in Existence / 1. Nature of Change
Change is nothing but movement [Hobbes]
     Full Idea: All mutation consists in motion only
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.09.06)
     A reaction: Another little gem of simplicity from Hobbes, and one with which I am inclined to agree. The value of a variable can 'change', but that may be metaphorical.
7. Existence / B. Change in Existence / 2. Processes
Four-dimensionalism sees things and processes as belonging in the same category [Sider]
     Full Idea: Four-dimensionalism does not respect a deep difference between thing-talk and process-talk, because it tends to place events and things in the same ontological category.
     From: Theodore Sider (Four Dimensionalism [2001], 6.1)
     A reaction: He then quotes Broad, Idea 14759. This idea is the best reason yet for being sympathetic to the four-dimensionalist view, because I think processes really must have a central place in any decent ontology.
7. Existence / C. Structure of Existence / 5. Supervenience / a. Nature of supervenience
Supervenience is a modal connection [Sider]
     Full Idea: Supervenience is just a kind of modal connection.
     From: Theodore Sider (Writing the Book of the World [2011], 09.10)
     A reaction: It says what would happen, as well as what does. This is big for Sider because he rejects modality as a feature of actuality. I think the world is crammed full of modal facts, so supervenience should be a handy tool for me.
7. Existence / C. Structure of Existence / 6. Fundamentals / b. Types of fundamental
Is fundamentality in whole propositions (and holistic), or in concepts (and atomic)? [Sider]
     Full Idea: The locus of fundamentality for a Finean is the whole proposition, whereas for me it is the proposition-part. Fundamentality is holistic for the Finean, atomistic for me.
     From: Theodore Sider (Writing the Book of the World [2011], 08.3)
     A reaction: This is because Kit Fine has pushed fundamentality into a relation (grounding), rather than into the particular entities involved (if I understand Sider's reading of him aright). My first intuition is to side with Sider. I'm on Sider's side...
Tables and chairs have fundamental existence, but not fundamental natures [Sider]
     Full Idea: The existence of tables and chairs is just as fundamental as the existence of electrons (in contrast, perhaps, with smirks and shadows, which do not exist fundamentally). However, tables and chairs have nonfundamental natures.
     From: Theodore Sider (Writing the Book of the World [2011], 08.7)
     A reaction: This seems to be a good clarification, and to me the 'nature' of something points towards its essence. However, I suppose he refers here to the place of something in a dependence hierarchy. But then, why does it have that place? What power?
7. Existence / C. Structure of Existence / 8. Stuff / a. Pure stuff
Unlike things, stuff obeys unrestricted composition and mereological essentialism [Sider]
     Full Idea: Stuff obeys unrestricted composition and mereological essentialism, whereas things do not.
     From: Theodore Sider (Writing the Book of the World [2011], 09.6.2)
     A reaction: [He cites Markosian 2004]
7. Existence / D. Theories of Reality / 6. Physicalism
Every part of the universe is body, and non-body is not part of it [Hobbes]
     Full Idea: The world is corporeal, that is to say, body...and every part of the universe is body, and that which is not body is no part of the universe.
     From: Thomas Hobbes (Leviathan [1651], IV.46)
     A reaction: [Hobbes concedes existence to visible spirits, but not invisible ones]. This is the kind of remark which got Hobbes hated. It is also the sort of thing that makes him the best candidate for the 'first modern man'.
7. Existence / D. Theories of Reality / 9. States of Affairs
We must distinguish 'concrete' from 'abstract' and necessary states of affairs. [Sider]
     Full Idea: The truthmaker theorist's 'concrete' states of affairs must be distinguished from necessarily existing 'abstract' states of affairs.
     From: Theodore Sider (Writing the Book of the World [2011], 08.4)
     A reaction: [He cites Plantinga's 'Nature of Necessity' for the second one; I presume the first one is Armstrong]
7. Existence / D. Theories of Reality / 10. Vagueness / f. Supervaluation for vagueness
A 'precisification' of a trivalent interpretation reduces it to a bivalent interpretation [Sider]
     Full Idea: For a 'precisification' we take a trivalent interpretation and preserve the T and F values, and then assign all the third values in some way to either T or F.
     From: Theodore Sider (Logic for Philosophy [2010], 3.4.5)
     A reaction: [my informal summary of Sider's formal definition]
Supervaluational logic is classical, except when it adds the 'Definitely' operator [Sider]
     Full Idea: Supervaluation preserves classical logic (even though supervaluations are three-valued), except when we add the Δ operator (meaning 'definitely' or 'determinately').
     From: Theodore Sider (Logic for Philosophy [2010], 3.4.5)
A 'supervaluation' assigns further Ts and Fs, if they have been assigned in every precisification [Sider]
     Full Idea: In a 'supervaluation' we take a trivalent interpretation, and assign to each wff T (or F) if it is T (or F) in every precisification, leaving the third truth-value in any other cases. The wffs are then 'supertrue' or 'superfalse' in the interpretation.
     From: Theodore Sider (Logic for Philosophy [2010], 3.4.5)
     A reaction: [my non-symbolic summary] Sider says the Ts and Fs in the precisifications are assigned 'in any way you like', so supervaluation is a purely formal idea, not a technique for eliminating vagueness.
We can 'sharpen' vague terms, and then define truth as true-on-all-sharpenings [Sider]
     Full Idea: We can introduce 'sharpenings', to make vague terms precise without disturbing their semantics. Then truth (or falsity) becomes true(false)-in-all-sharpenings. You are only 'rich' if you are rich-on-all-sharpenings of the word.
     From: Theodore Sider (Logic for Philosophy [2010], 3.4.5)
     A reaction: Not very helpful. Lots of people might be considered rich in many contexts, but very few people would be considered rich in all contexts. You are still left with some vague middle ground.
7. Existence / D. Theories of Reality / 11. Ontological Commitment / d. Commitment of theories
Accept the ontology of your best theory - and also that it carves nature at the joints [Sider]
     Full Idea: We can add to the Quinean advice to believe the ontology of your best theory that you should also regard the ideology of your best theory as carving at the joints.
     From: Theodore Sider (Writing the Book of the World [2011], 02.3)
     A reaction: I've never liked the original Quinean formulation, but this is much better. I just take my ontological commitments to reside in me, not in whatever theory I am currently employing. I may be dubious about my own theory.
8. Modes of Existence / A. Relations / 1. Nature of Relations
A relation is a feature of multiple objects taken together [Sider]
     Full Idea: A relation is just a feature of multiple objects taken together.
     From: Theodore Sider (Logic for Philosophy [2010], 1.8)
     A reaction: Appealingly simple, especially for a logician, who can then just list the relevant objects as members of a set, and the job is done. But if everyone to the left of me is also taller than me, this won't quite do.
8. Modes of Existence / B. Properties / 3. Types of Properties
A property is intrinsic if an object alone in the world can instantiate it [Sider]
     Full Idea: Chisholm and Kim proposed a modal notion of an 'intrinsic' property - that a property is intrinsic if and only if it is possibly instantiated by an object that is alone in the world.
     From: Theodore Sider (Writing the Book of the World [2011], 01.2)
     A reaction: [He cites Chisholm 1976:127 and Kim 1982:59-60] Sider then gives a counterexample from David Lewis (Idea 14979).
8. Modes of Existence / B. Properties / 6. Categorical Properties
Proper ontology should only use categorical (actual) properties, not hypothetical ones [Sider]
     Full Idea: A proper ontology should invoke only categorical, or occurrent, properties and relations. Categorical properties involve what objects are actually like, whereas hypothetical properties 'point beyond' their instances.
     From: Theodore Sider (Four Dimensionalism [2001], 2.3)
     A reaction: This spectacularly leaves out powers and dispositions, which are actual properties which 'point beyond' their instances! This is the nub of the powers debate, and the most interesting topic in modern metaphysics.
8. Modes of Existence / B. Properties / 8. Properties as Modes
Accidents are just modes of thinking about bodies [Hobbes]
     Full Idea: An accident is a mode of conceiving a body.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.02)
     A reaction: In contrast to the other thinkers who followed Suárez on modes in the early 17th century, Hobbes thinks they are just ways of 'conceiving' bodies, rather than actual features of them.
8. Modes of Existence / B. Properties / 10. Properties as Predicates
Predicates can be 'sparse' if there is a universal, or if there is a natural property or relation [Sider]
     Full Idea: For Armstrong a predicate is sparse when there exists a corresponding universal; for Lewis, a predicate is sparse when there exists a corresponding natural property or relation.
     From: Theodore Sider (Writing the Book of the World [2011], 06)
     A reaction: I like 'sparse' properties, but have no sympathy with Armstrong, and am cautious about Lewis. I like Shoemaker's account, which makes properties even sparser. 'Abundant' so-called properties are my pet hate. They are 'predicates'!
8. Modes of Existence / B. Properties / 12. Denial of Properties
Accidents are not parts of bodies (like blood in a cloth); they have accidents as things have a size [Hobbes]
     Full Idea: An accident's being in a body is not to be taken as something contained in that body - as if redness were in blood like blood in a bloody cloth, as part of the whole, for then accident would be a body. It is like body having size or rest or movement.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.03)
     A reaction: [compressed] Hobbes is fishing for something like the Quinean view of properties, but no one seems to be able to articulate this sceptical view very well. Pasnau says he means to talk of 'the mode of conceiving a body' (De C 8.2).
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
The complete power of an event is just the aggregate of the qualities that produced it [Hobbes]
     Full Idea: The power of agent and patient taken together, which may be called the complete power, is the same as the complete cause, for each consists in the aggregation together of all the accidents that are required to produce an effect in both agent and patient.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.10.01)
     A reaction: They treat powers as macro phenomena, and don't seem to have a sense of the basic powers that build up the big picture.
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
The only generalities or universals are names or signs [Hobbes]
     Full Idea: Nothing is general or universal besides names or signs.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.05)
     A reaction: This is the perfect motto for nominalists, among which I am inclined to include myself. Hobbes had a fabulous gift for economy of phrasing. This website is dedicated to that ideal. Reality does not contain generalities (obviously!!).
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
Bodies are independent of thought, and coincide with part of space [Hobbes]
     Full Idea: A body is that, which having no dependence on our thought, is coincident or coextended with some part of space.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.01)
     A reaction: This rather Cartesian view doesn't seem to offer any distinction between empty space and space containing an 'object'. Presumably it is the ancestor of the Quinean account just in terms of space-time points. Don't like it.
If you separate the two places of one thing, you will also separate the thing [Hobbes]
     Full Idea: One body cannot be in two places at the same time, ...for the place that a body fills being divided into two, the placed body will also be divided into two; the place and the body that fills that place are divided both together.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.08)
     A reaction: If every time you manipulated one body it affected both of them, you might say that one body was in two places, rather like a mirror image.
If you separated two things in the same place, you would also separate the places [Hobbes]
     Full Idea: Two bodies cannot be together in the same place, ..because when a body that fills its whole place is divided into two, the place itself is divided into two also, so that there will be two places.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.08)
     A reaction: The wonderful things about philosophy is that you are faced with obvious truths of the world, and cannot begin to think why they are true - and then up steps a philosopher and offers you a reason.
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
If sortal terms fix the kind and the persistence conditions, we need to know what kinds there are [Sider]
     Full Idea: Followers of the view that every entity is associated with some sortal term that answers the question 'what kind of thing is this?', and determines its persistence conditions, must answer the question what kinds of entity there are.
     From: Theodore Sider (Four Dimensionalism [2001], 5.3)
     A reaction: [He explicitly refers to David Wiggins here] In other words Wiggins has got it the wrong way round, which is my own view of his theory. Sortal terms don't grow on the trees in the Garden of Eden, available for applications.
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
If a whole body is moved, its parts must move with it [Hobbes]
     Full Idea: How can any whole body be moved, unless all its parts be moved together with it?
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.05)
     A reaction: This might be a distinguishing mark for a whole physical body. I think it is probably the main mark for ordinary folk. I've never found this idea in Aristotle.
9. Objects / B. Unity of Objects / 3. Unity Problems / b. Cat and its tail
If Tib is all of Tibbles bar her tail, when Tibbles loses her tail, two different things become one [Sider]
     Full Idea: This powerful puzzle (known to the Stoics, introduced by Geach, popularised by Wiggins) has a cat Tibbles and a proper part Tib, which is all of Tibbles except the tail. If Tibbles loses her tail, the two were distinct, but they now coincide.
     From: Theodore Sider (Four Dimensionalism [2001], 5.1)
     A reaction: [compressed] Compare a few people leave a football ground, and what was a large part of the crowd becomes the whole of the crowd. Which suggests that there is no problem if cats are like crowds. But we don't like that view of cats.
9. Objects / B. Unity of Objects / 3. Unity Problems / c. Statue and clay
Artists 'create' statues because they are essentially statues, and so lack identity with the lump of clay [Sider]
     Full Idea: Presumably it is claimed that the artist 'created' the statue because the object created is essentially a statue, and thus cannot be identified with the unformed lump of clay with which the artist began.
     From: Theodore Sider (Four Dimensionalism [2001])
     A reaction: This is based on Burke's views. This is sortal essentialism, rather than my own view of essence as an inner explanatory mechanism or form. If an old abstract sculpture was no longer recognised as a statue, would it necessarily still be a statue?
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
The stage view of objects is best for dealing with coincident entities [Sider]
     Full Idea: There are numerous cases in which there is pressure to admit coincident entities. The best way of coming to grips with this, I think, invokes the stage view. ...In the worm theory, coincident objects are no more mysterious than overlapping roads.
     From: Theodore Sider (Four Dimensionalism [2001], 5.1)
     A reaction: At this point I get nervous if in order to 'get to grips' with a phenomenon which is hard to articulate but obvious to common sense, we have to invoke a rather startling metaphysics that completely upends the common sense we started with.
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
A chair is wood, and its shape is the form; it isn't 'compounded' of the matter and form [Hobbes]
     Full Idea: Nothing can be compounded of matter and form. The matter of a chair is wood; the form is the figure it has, apt for the intended use. Does his Lordship think the chair compounded of the wood and the figure?
     From: Thomas Hobbes (Letter to Bramhall [1650], 4:302), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 07.1
     A reaction: Aristotle does use the word 'shape' [morphe] when he is discussing hylomorphism, and the statue example seems to support it, but elsewhere the form is a much deeper principle of individuation.
9. Objects / C. Structure of Objects / 5. Composition of an Object
'Composition as identity' says that an object just is the objects which compose it [Sider]
     Full Idea: 'Composition as identity' says that when a thing, x, is composed of some other objects, the ys, then this is a kind of identity between the x and the ys. The industrial-strength version says object x just is the ys. Lewis says it is just an analogy.
     From: Theodore Sider (Four Dimensionalism [2001], 5.3)
     A reaction: I am averse to such a doctrine, as is Leibniz, with his insistence that an aggregate is not a unity. There has to be some sort of principle that bestows oneness on a many. I take this to be structural, and is an elucidation of hylomorphism.
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
A body is always the same, whether the parts are together or dispersed [Hobbes]
     Full Idea: A body is always the same, whether the parts of it be put together or dispersed; or whether it be congealed or dissolved.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
     A reaction: This appears to be a commitment by Hobbes to what we now call 'classical' mereology - that any bunch of things can count as a whole, whether they are together or dispersed. He seems to mean more than a watch surviving dismantling.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
To make a whole, parts needn't be put together, but can be united in the mind [Hobbes]
     Full Idea: In composition, it is to be understood that for the making up of a whole there is no need of putting the parts together, so as to make them touch one another, but only of collecting them into one sum in the mind.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.07.08)
     A reaction: This seems to the 'unrestricted composition' of classical mereology, since it appears that Hobbes offers no restriction on which parts can be united by a mind, no matter how bizarre.
9. Objects / D. Essence of Objects / 5. Essence as Kind
Particulars contain universal things [Hobbes]
     Full Idea: Universal things are contained in the nature of singular things.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.04)
     A reaction: That is the neatest and most accurate summary of the situation I have ever read. Particulars come first, but they are all riddled with generalities (but that is not as well said as Hobbes's remark).
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
Some accidental features are permanent, unless the object perishes [Hobbes]
     Full Idea: There are certain accidents which can never perish except the body perish also.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.03)
     A reaction: He is just making an observation, and not proposing a theory about essence.
9. Objects / D. Essence of Objects / 12. Essential Parts
Mereological essentialism says an object's parts are necessary for its existence [Sider]
     Full Idea: Mereological essentialism says that an object's parts are necessary for its existence. ....It is literally never correct to say that an thing survives a change in its parts.
     From: Theodore Sider (Four Dimensionalism [2001], 5.7)
     A reaction: Chisholm is well known for proposing this view. Sider adds a possible toughening clause, that the parts are also sufficient for the object's existence. This is a philosophers' notion of identity, not the normal English language concept.
9. Objects / D. Essence of Objects / 13. Nominal Essence
The feature which picks out or names a thing is usually called its 'essence' [Hobbes]
     Full Idea: That accident for which we give a certain name to any body, or the accident which denominates its subject, is commonly called the essence thereof.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.23)
     A reaction: This is clearly a prelude to Locke's more carefully formulated 'nominal essence'. Fairly obvious, for nominalist empiricists. A bit surprising to say this was 'common'.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Essence is just an artificial word from logic, giving a way of thinking about substances [Hobbes]
     Full Idea: Essence and all other abstract names are words artificial belonging to the art of logic, and signify only the manner how we consider the substance itself.
     From: Thomas Hobbes (Letter to Bramhall [1650], 4:308), quoted by Robert Pasnau - Metaphysical Themes 1274-1671
     A reaction: I sympathise quite a lot with this view, but not with its dismissive tone. The key question I take to be: if you reject essences entirely (having read too much physics), how are we going to think about entities in the world in future?
Essence (even if nonmodal) is not fundamental in metaphysics [Sider]
     Full Idea: We should not regard nonmodal essence as being metaphysically basic: fundamental theories need essence no more than they need modality.
     From: Theodore Sider (Writing the Book of the World [2011], 12.1)
     A reaction: He is discussing Kit Fine, and notes that Fine offers a nonmodal view of essence, but still doesn't make it fundamental. I am a fan of essences, but making them fundamental in metaphysics seems unlikely.
9. Objects / E. Objects over Time / 3. Three-Dimensionalism
Three-dimensionalists assert 'enduring', being wholly present at each moment, and deny 'temporal parts' [Sider]
     Full Idea: Three-dimensionalists say that things have no 'temporal parts', that they 'endure', and that they are wholly present at every moment of their careers.
     From: Theodore Sider (Four Dimensionalism [2001], 3)
     A reaction: An obvious problem case for being wholly present would be the building and fitting of a large ship, where it might seem to be present before it was wholly present.
Some might say that its inconsistency with time travel is a reason to favour three-dimensionalism [Sider]
     Full Idea: Some might even regard inconsistency with time travel as an advantage of three-dimensionalism, as a vindication of a prior belief that time travel is impossible! I see no merit in these claims.
     From: Theodore Sider (Four Dimensionalism [2001], 7.2)
     A reaction: I do! Sider cheerfully says that there are good reasons to believe that time travel is possible, and then use this possibility to support his four-dimensional view, but I personally doubt his assumption. The evidence for time travel is flimsy and obscure.
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
Four-dimensionalists assert 'temporal parts', 'perduring', and being spread out over time [Sider]
     Full Idea: Four-dimensionalists say that things have 'temporal parts', that they 'perdure', and that they are spread out over time.
     From: Theodore Sider (Four Dimensionalism [2001], 3)
4D says intrinsic change is difference between successive parts [Sider]
     Full Idea: For four-dimensionalists intrinsic change is difference between successive temporal parts.
     From: Theodore Sider (Four Dimensionalism [2001], 3.2)
     A reaction: This attempts a reply to the commonest criticism of four-dimensionalism - that you can't explain change if you don't have one enduring thing which undergoes the change. I get stuck of the question 'how big (temporally) is a part?'.
4D says each spatiotemporal object must have a temporal part at every moment at which it exists [Sider]
     Full Idea: Four-dimensionalism may be formulated as the claim that, necessarily, each spatiotemporal object has a temporal part at every moment at which it exists.
     From: Theodore Sider (Four Dimensionalism [2001], 3.2)
     A reaction: If there were tiny quantum gaps between temporal parts, that would presumably ruin the story. On this view an object has to be a 'worm', to be the thing which has the parts.
9. Objects / E. Objects over Time / 5. Temporal Parts
Temporal parts exist, but are not prior building blocks for objects [Sider]
     Full Idea: My four-dimensionalism implies the existence of temporal parts, but not that those parts are more fundamental, nor that the object is 'constructed' from its parts, nor that identity over time is reducible to parts.
     From: Theodore Sider (Four Dimensionalism [2001], 3.2)
     A reaction: That's a rather negative account of temporal parts, which makes you ask what their positive role could be. Do they contribute anything to our understanding of a temporally extended object?
Temporal parts are instantaneous [Sider]
     Full Idea: Unless otherwise noted, I will think of temporal parts as being instantaneous.
     From: Theodore Sider (Four Dimensionalism [2001], 3.2)
     A reaction: This comes up against all the Augustinian worries about the intrinsic nature of time. How many temporal parts does a typical object possess? Is a third temporal part always to be found between any two of them? How do they 'connect'?
How can an instantaneous stage believe anything, if beliefs take time? [Sider]
     Full Idea: How can an instantaneous stage believe anything? Beliefs take time.
     From: Theodore Sider (Four Dimensionalism [2001], 5.8)
     A reaction: Sider's four-dimensionalist answer is that the belief is embodied in the earlier counterparts, making belief a 'highly relational property'. I am not impressed by this answer to the very nice problem which he has raised. It's a problem for 3D, too.
Four-dimensionalism says temporal parts are caused (through laws of motion) by previous temporal parts [Sider]
     Full Idea: The sensible four-dimensionalist will claim that current temporal parts are caused to exist by previous temporal parts. The laws that govern this process are none other than the familiar laws of motion.
     From: Theodore Sider (Four Dimensionalism [2001], 6.3)
     A reaction: I keep struggling with the instantaneous natural of temporal parts, and now I find that they have to do the job of being causal relata. When do they do their job? They've gone home before they've finished clocking in. Continuance requires motion?
9. Objects / E. Objects over Time / 8. Continuity of Rivers
It is the same river if it has the same source, no matter what flows in it [Hobbes]
     Full Idea: That will be the same river which flows from one and the same fountain, whether the same water, or other water, or something other than water, flow thence.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
     A reaction: This makes the source the one necessity for a river. I think the end matters too. If the Thames reversed direction, and flowed into Wales, it would not be the Thames any more.
9. Objects / E. Objects over Time / 9. Ship of Theseus
Some individuate the ship by unity of matter, and others by unity of form [Hobbes]
     Full Idea: In the Ship of Theseus, some place individuity in the unity of matter; others, in the unity of form.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
     A reaction: Simons raises this comment into a dogma, that there are at least two objects present in the ship. If I offered you a sum for the contents of your house, they would have a unity of monetary value.
If a new ship were made of the discarded planks, would two ships be numerically the same? [Hobbes]
     Full Idea: If some man kept the old planks as they were taken out, and by putting them afterwards together again in the same order, had again made a ship of them, ...there would have been two ships numerically the same, which is absurd.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
     A reaction: This is the origin of the famous modern problematical example of the Ship of Theseus. The ancient example is just the case of whether you step into the same river, but using an artefact with parts, to make it clearer.
The ship undergoes 'asymmetric' fission, where one candidate is seen as stronger [Sider]
     Full Idea: The Ship of Theseus seems to be a case of 'asymmetric' fission (where one resultant entity has a stronger claim). Many see the continuously rebuilt ship as the stronger candidate, but each candidate, without the other, would be the original ship.
     From: Theodore Sider (Four Dimensionalism [2001], 5.1)
9. Objects / F. Identity among Objects / 3. Relative Identity
As an infant, Socrates was not the same body, but he was the same human being [Hobbes]
     Full Idea: It makes a great difference to ask concerning Socrates whether he is the same human being or whether he is the same body. For his body, when he is old, cannot be the same it was when he was an infant. …He can, however, be the same human being.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.07)
     A reaction: This is not commitment to full (Geachian) relative identity, but it notes the problem.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The identity of indiscernibles is necessarily true, if being a member of some set counts as a property [Sider]
     Full Idea: The identity of indiscernibles (∀x∀y(∀X(Xx↔Xy)→x=y) is necessarily true, provided that we construe 'property' very broadly, so that 'being a member of such-and-such set' counts as a property.
     From: Theodore Sider (Logic for Philosophy [2010], 5.4.3)
     A reaction: Sider's example is that if the two objects are the same they must both have the property of being a member of the same singleton set, which they couldn't have if they were different.
9. Objects / F. Identity among Objects / 8. Leibniz's Law
If you say Leibniz's Law doesn't apply to 'timebound' properties, you are no longer discussing identity [Sider]
     Full Idea: If someone is in pain at t1 and not at t2, we might restrict Leibniz's Law so as not to apply to 'timebound' properties, ..but this is deeply unsatisfying, ...and forfeits one's claim to be discussing identity. The demands of identity are high.
     From: Theodore Sider (Four Dimensionalism [2001], 5.5)
     A reaction: [on Myro 1986] Sider's response is unsatisfying. It means a thing loses its identity (with itself?) if it has even a tiny fluctuating in its properties. Quantum changes then destroy all notions of identity. English-speakers don't use 'identity' like that.
Two bodies differ when (at some time) you can say something of one you can't say of the other [Hobbes]
     Full Idea: Two bodies are said to differ from one another, when something may be said of one of them, which cannot be said of the other at the same time.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.11.02)
     A reaction: Note the astute addition of 'at the same time'. Note also that it is couched in terms of what is true, rather than in terms of 'properties' or 'accidents'.
10. Modality / A. Necessity / 3. Types of Necessity
'Strong' necessity in all possible worlds; 'weak' necessity in the worlds where the relevant objects exist [Sider]
     Full Idea: 'Strong necessity' requires the truth of 'necessarily φ' is all possible worlds. 'Weak necessity' merely requires that 'necessarily φ' be true in all worlds in which objects referred to within φ exist.
     From: Theodore Sider (Logic for Philosophy [2010], 9.6.3)
     A reaction: This seems to be a highly desirably distinction, given the problem of Idea 13719. It is weakly necessary that humans can't fly unaided, assuming we are referring the current feeble wingless species. That hardly seems to be strongly necessary.
10. Modality / A. Necessity / 5. Metaphysical Necessity
Maybe metaphysical accessibility is intransitive, if a world in which I am a frog is impossible [Sider]
     Full Idea: Some argue that metaphysical accessibility is intransitive. The individuals involved mustn't be too different from the actual world. A world in which I am a frog isn't metaphysically possible. Perhaps the logic is modal system B or T.
     From: Theodore Sider (Logic for Philosophy [2010], 6.3.1)
     A reaction: This sounds rather plausible and attractive to me. We don't want to say that I am necessarily the way I actually am, though, so we need criteria. Essence!
10. Modality / A. Necessity / 6. Logical Necessity
Logical truths must be necessary if anything is [Sider]
     Full Idea: On any sense of necessity, surely logical truths must be necessary.
     From: Theodore Sider (Logic for Philosophy [2010], 6.4)
10. Modality / B. Possibility / 5. Contingency
'Contingent' means that the cause is unperceived, not that there is no cause [Hobbes]
     Full Idea: For contingent, men do not mean that which hath no cause, but that which hath not for cause any thing that we perceive, as when a traveller meets a shower, they both had sufficient causes, but they didn't cause one another, so we say it was contingent.
     From: Thomas Hobbes (Of Liberty and Necessity [1654], §95)
     A reaction: Contingent nowadays means 'might not have happened', or 'does not happen in all possible worlds'. Personally I share Hobbes' doubts about the concept of contingency, and this is quite a good account of the misunderstanding.
10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional
'If B hadn't shot L someone else would have' if false; 'If B didn't shoot L, someone else did' is true [Sider]
     Full Idea: To show the semantic difference between counterfactuals and indicative conditionals, 'If Booth hadn't shot Lincoln someone else would have' is false, but 'If Booth didn't shoot Lincoln then someone else did' is true.
     From: Theodore Sider (Logic for Philosophy [2010], 8)
     A reaction: He notes that indicative conditionals also differ in semantics from material and strict conditionals. The first example allows a world where Lincoln was not shot, but the second assumes our own world, where he was. Contextual domains?
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Humeans say that we decide what is necessary [Sider]
     Full Idea: The spirit of Humeanism is that necessity is not a realm to be discovered. We draw the lines around what is necessary.
     From: Theodore Sider (Writing the Book of the World [2011], 12.3)
     A reaction: I disagree, but it is hard to argue the point. My intuitions are that the obvious necessities of logic and mathematics reflect the way nature has to be. The deepest necessities are patterns (about which God has no choice).
Modal terms in English are entirely contextual, with no modality outside the language [Sider]
     Full Idea: English modals are context-dependent through and through; there is no stable 'outer modality'.
     From: Theodore Sider (Writing the Book of the World [2011], 12.7)
     A reaction: Sider has been doing so well up to here. To me this is swallowing the bait of linguistic approaches to philosophy which he has fought so hard to avoid.
10. Modality / C. Sources of Modality / 3. Necessity by Convention
If truths are necessary 'by convention', that seems to make them contingent [Sider]
     Full Idea: If □φ says that φ is true by convention, then □φ would apparently turn out to be contingent, since statements about what conventions we adopt are not themselves true by convention. The main axioms of S4 and S5 would be false.
     From: Theodore Sider (Writing the Book of the World [2011], 12.1)
Conventionalism doesn't seem to apply to examples of the necessary a posteriori [Sider]
     Full Idea: Conventionalism is apparently inapplicable to Kripke's and Putnam's examples of the necessary a posteriori (and, relatedly, to de re modality).
     From: Theodore Sider (Writing the Book of the World [2011], 12.1)
     A reaction: [Sidelle 1989 discusses this]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
Humeans says mathematics and logic are necessary because that is how our concept of necessity works [Sider]
     Full Idea: Why are logical (or mathematical, or analytic...) truths necessary? The Humean's answer is that this is just how our concept of necessity works.
     From: Theodore Sider (Writing the Book of the World [2011], 12.11)
     A reaction: This is why I (unlike Sider) am not a Humean. If we agreed that 'necessary' meant 'whatever is decreed by the Pope', that would so obviously not be necessary that we would have to start searching nature for true necessities.
10. Modality / C. Sources of Modality / 5. Modality from Actuality
The world does not contain necessity and possibility - merely how things are [Sider]
     Full Idea: At bottom, the world is an amodal place. Necessity and possibility do not carve at the joints; ultimate reality is not 'full of threats and promises' (Goodman). The book of the world says how things are, not how they must or might be.
     From: Theodore Sider (Writing the Book of the World [2011], 12)
     A reaction: Nice to see this expressed so clearly. I find it much easier to disagree with as a result. At first blush I would say that if you haven't noticed that the world is full of threats and promises, you should wake up and smell the coffee. Actuality is active.
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
We can imagine a point swelling and contracting - but not how this could be done [Hobbes]
     Full Idea: Even if we can feign in our mind that a point swells to a huge bulk and then contracts to a point - imagining something's made from nothing (ex nihilo), and nothing's made from something - still we cannot comprehend how this could be done in nature.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.20)
     A reaction: [compressed] Pasnau notes that this offers two sorts of conceivability, of something happening, and of a reason for it happening. A really nice idea, significant (I think) for scientific essentialists, who say possibilities are fewer than you think.
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
Transworld identity is not a problem in de dicto sentences, which needn't identify an individual [Sider]
     Full Idea: There is no problem of transworld identification with de dicto modal sentence, for their evaluation does not require taking an individual from one possible world and reidentifying it in another.
     From: Theodore Sider (Logic for Philosophy [2010], 9.2)
     A reaction: If 'de dicto' is about the sentence and 'de re' is about the object (Idea 5732), how do you evaluate the sentence without at least some notion of the object to which it refers. Nec the Prime Minister chairs the cabinet. Could a poached egg do the job?
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
Counterparts rest on similarity, so there are many such relations in different contexts [Sider]
     Full Idea: A counterpart relation is a similarity relation. Since there are different dimensions of similarity, there are different counterpart relations.
     From: Theodore Sider (Four Dimensionalism [2001], 6.4)
10. Modality / E. Possible worlds / 3. Transworld Objects / e. Possible Objects
Barcan Formula problem: there might have been a ghost, despite nothing existing which could be a ghost [Sider]
     Full Idea: A problem with the Barcan Formula is it might be possible for there to exist a ghost, even though there in fact exists nothing that could be a ghost. There could have existed some 'extra' thing which could be a ghost.
     From: Theodore Sider (Logic for Philosophy [2010], 9.5.2)
     A reaction: Thus when we make modal claims, do they only refer to what actually exists, or is specified in our initial domain? Can a claim enlarge the domain? Are domains 'variable'? Simple claims about what might have existed seem to be a problem.
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
The qualities of the world are mere appearances; reality is the motions which cause them [Hobbes]
     Full Idea: Whatsoever accidents or qualities our senses make us think there be in the world, they are not there, but are seemings and apparitions only. The things that really are in the world without us are those motions by which these seemings are caused.
     From: Thomas Hobbes (The Elements of Law [1640], I.2.10), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 10.2
     A reaction: This seems to count as a sense-datum theory, rather than a representative theory of perception, since it makes no commitment to the qualities containing any accurate information at all. We just start from the qualities and try to work it out.
Appearance and reality can be separated by mirrors and echoes [Hobbes]
     Full Idea: If colours or sounds were in the bodies or objects that cause them, they could not be severed from them, as by glasses, and in echoes by reflection, we see they are; where we know the thing we see is in one place, the appearance in another.
     From: Thomas Hobbes (Leviathan [1651], 1.01)
12. Knowledge Sources / D. Empiricism / 1. Empiricism
Evidence is conception, which is imagination, which proceeds from the senses [Hobbes]
     Full Idea: All evidence is conception, as it is said, and all conception is imagination and proceeds from sense. And spirits we suppose to be those substances which work not upon the sense, and therefore not conceptible.
     From: Thomas Hobbes (The Elements of Law [1640], I.11.5), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 16.2
     A reaction: This is exactly the same as Hume's claim that all ideas are the result of impressions, and is the very essence of empiricism. We see here that such an epistemology can have huge consequences.
Experience can't prove universal truths [Hobbes]
     Full Idea: Experience concludeth nothing universally.
     From: Thomas Hobbes (The Elements of Law [1640], I.4.10), quoted by Richard Tuck - Hobbes Ch.2
     A reaction: Empiricists seem proud to claim this limitation on human understanding, where rationalists like Leibniz use it as an argument against empiricism. Kripke says (e.g. Idea 4966) they are both wrong! I sympathise with Kripke.
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius]
     Full Idea: Anaxarchus said that he was not even sure that he knew nothing.
     From: report of Anaxarchus (fragments/reports [c.340 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.10.1
13. Knowledge Criteria / D. Scepticism / 5. Dream Scepticism
Dreams must be false because they seem absurd, but dreams don't see waking as absurd [Hobbes]
     Full Idea: Because waking I often observe the absurdity of dreams, but never dream of the absurdity of my waking thoughts, I am well satisfied that, being awake, I know I dream not, though when I dream I think myself awake.
     From: Thomas Hobbes (Leviathan [1651], 1.02)
14. Science / B. Scientific Theories / 2. Aim of Science
A theory which doesn't fit nature is unexplanatory, even if it is true [Sider]
     Full Idea: 'Theories' based on bizarre, non-joint-carving classifications are unexplanatory even when true.
     From: Theodore Sider (Writing the Book of the World [2011], 03.1)
     A reaction: This nicely pinpoints why I take explanation to be central to whole metaphysical enterprise.
14. Science / B. Scientific Theories / 8. Ramsey Sentences
If I used Ramsey sentences to eliminate fundamentality from my theory, that would be a real loss [Sider]
     Full Idea: If the entire theory of this book were replaced by its Ramsey sentence, omitting all mention of fundamentality, something would seem to be lost.
     From: Theodore Sider (Writing the Book of the World [2011], 02.2 n2)
     A reaction: It is a moot point whether Ramsey sentences actually eliminate anything from the ontology, but trying to wriggle out of ontological commitment looks a rather sad route to follow.
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
Problem predicates in induction don't reflect the structure of nature [Sider]
     Full Idea: 'Is nonblack', 'is a nonraven', and 'grue' fail to carve at the joints.
     From: Theodore Sider (Writing the Book of the World [2011], 03.3)
     A reaction: A lot more than this needs to said, but this remark encapsulates why I find most of these paradoxes of induction uninteresting. They are all the creations of logicians, rather than of scientists.
Two applications of 'grue' do not guarantee a similarity between two things [Sider]
     Full Idea: The applicability of 'grue' to each of a pair of particulars does not guarantee the similarity of those particulars.
     From: Theodore Sider (Writing the Book of the World [2011], 06.2)
     A reaction: Grue is not a colour but a behaviour. If two things are 'mercurial' or 'erratic', will that ensure a similarity at any given moment?
14. Science / C. Induction / 6. Bayes's Theorem
Bayes produces weird results if the prior probabilities are bizarre [Sider]
     Full Idea: In the Bayesian approach, bizarre prior probability distributions will result in bizarre responses to evidence.
     From: Theodore Sider (Writing the Book of the World [2011], 03.3)
     A reaction: This is exactly what you find when people with weird beliefs encounter ridiculous evidence for things. It doesn't invalidate the formula, but just says rubbish in rubbish out.
14. Science / D. Explanation / 1. Explanation / a. Explanation
Explanations must cite generalisations [Sider]
     Full Idea: Explanations must cite generalisations.
     From: Theodore Sider (Writing the Book of the World [2011], 07.13)
     A reaction: I'm uneasy about this. Presumably some events have a unique explanation - a unique mechanism, perhaps. Language is inescapably general in its nature - which I take to be Aristotle's reason for agreeing the Sider. [Sider adds mechanisms on p.159]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Science aims to show causes and generation of things [Hobbes]
     Full Idea: The end of science is the demonstration of the causes and generation of things.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.13)
14. Science / D. Explanation / 3. Best Explanation / b. Ultimate explanation
If the ultimate explanation is a list of entities, no laws, patterns or mechanisms can be cited [Sider]
     Full Idea: Ultimate explanations always terminate in the citation of entities; but since a mere list of entities is so unstructured, these 'explanations' cannot be systematized with detailed general laws, patterns, or mechanisms.
     From: Theodore Sider (Writing the Book of the World [2011], 08.5)
     A reaction: We just need to distinguish between ultimate ontology and ultimate explanations. I think explanations peter out at the point where we descend below the mechanisms. Patterns or laws don't explain on their own. Causal mechanisms are the thing.
15. Nature of Minds / B. Features of Minds / 4. Intentionality / a. Nature of intentionality
Intentionality is too superficial to appear in the catalogue of ultimate physics [Sider]
     Full Idea: One day the physicists will complete the catalogue of ultimate and irreducible properties of things. When they do, the like of spin, charm and charge will perhaps appear on the list. But aboutness sure won't; intentionality simply doesn't go that deep.
     From: Theodore Sider (Writing the Book of the World [2011], 4 Intro)
     A reaction: Fodor's project is to give a reductive, and perhaps eliminative, account of intentionality of mind, while leaving open what one might do with the phenomenological aspects. Personally I don't think they will appear on the list either.
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
Imagination is just weakened sensation [Hobbes]
     Full Idea: Imagination is nothing else but sense decaying or weakened by the absence of the object.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 4.25.07)
     A reaction: This sounds more like memory than imagination. He needs to say something about unusual combinations of memories, I would have thought.
15. Nature of Minds / C. Capacities of Minds / 10. Conatus/Striving
A 'conatus' is an initial motion, experienced by us as desire or aversion [Hobbes, by Arthur,R]
     Full Idea: Hobbes' notion of 'conatus' is a 'beginning of motion' - a motion through a point of space in an instant of time. In a human subject this is experience as desire or aversion. It thus forms a bridge between physics and psychology.
     From: report of Thomas Hobbes (De Corpore (Elements, First Section) [1655], p.178) by Richard T.W. Arthur - Leibniz 3 'Worlds'
     A reaction: This sounds rather like the primitive concept of a power which I like, but the term seems to be used very vaguely, and never discussed carefully. The idea provoked Leibniz to connect physical force with mental life.
16. Persons / F. Free Will / 5. Against Free Will
If a man suddenly develops an intention of doing something, the cause is out of his control, not in his will [Hobbes]
     Full Idea: When first a man hath an appetite or will to something, to which immediately before he had no appetite or will, the cause of his will is not the will itself, but something else not in his own disposing.
     From: Thomas Hobbes (Letters to the Lord Marquis of Newcastle [1652])
Freedom is absence of opposition to action; the idea of 'free will' is absurd [Hobbes]
     Full Idea: If a man should talk to me of a 'free-will', or any 'free' but free from being hindered by opposition, I should not say that he were in an error, but that his words were without a meaning, that is to say, absurd.
     From: Thomas Hobbes (Leviathan [1651], 1.05)
Those actions that follow immediately the last appetite are voluntary [Hobbes]
     Full Idea: Those actions that follow immediately the last appetite are voluntary.
     From: Thomas Hobbes (Letters to the Lord Marquis of Newcastle [1652])
A man cannot will to will, or will to will to will, so the idea of a voluntary will is absurd [Hobbes]
     Full Idea: The will is not voluntary: for a man can no more say he will will, than he will will will, and so make an infinite repetition of the word 'will', which is absurd and insignificant.
     From: Thomas Hobbes (Human Nature [1640], Ch.XII.5)
     A reaction: A nice simple point, allied to Nietzsche's notion that thoughts are uncontrollable (Idea 2291). Even Aquinas, who is quite a fan of free will, spotted the problem (Idea 1854). Personally I agree with Hobbes. Free will is a shibboleth.
16. Persons / F. Free Will / 7. Compatibilism
Liberty and necessity are consistent, as when water freely flows, by necessity [Hobbes]
     Full Idea: Liberty and necessity are consistent: as in the water, that hath not only liberty, but a necessity of descending by the channel.
     From: Thomas Hobbes (Leviathan [1651], II.Ch.XI)
     A reaction: Hume asserts something similar (Idea 2223), but they both miss the point, which is that libertarians about water would have to believe it didn't need to follow gravity, but could refuse to flow. Freedom of will and freedom of action are quite different.
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
Conceptions and apparitions are just motion in some internal substance of the head [Hobbes]
     Full Idea: Conceptions and apparitions are nothing really, but motion in some internal substance of the head.
     From: Thomas Hobbes (Human Nature [1640], Ch.VII.1)
     A reaction: Note that he carefully covers both thought in concepts and thought in images, and also that he is not saying that thought is the substance, but that it is a 'motion'. This strikes me as an excellent word, and I think Hobbes is right.
Sensation is merely internal motion of the sentient being [Hobbes]
     Full Idea: Sense in the sentient, can be nothing else but motion in some of the internal parts of the sentient; and the parts so moved are parts of the organs of sense.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 3.15.02)
     A reaction: Amazingly bold for the time, and presumably influenced by Lucretius. I am sympathetic, but to suggest that sensation is nothing more sounds a bit like a category mistake. Has he grasped that the brain is involved?
18. Thought / A. Modes of Thought / 3. Emotions / e. Basic emotions
The 'simple passions' are appetite, desire, love, aversion, hate, joy, and grief [Hobbes, by Goldie]
     Full Idea: For Hobbes the 'simple passions' were appetite, desire, love, aversion, hate, joy, and grief.
     From: report of Thomas Hobbes (Leviathan [1651], I.6) by Peter Goldie - The Emotions 4 'Evidence'
     A reaction: This is the standard approach to emotions of Hobbes's time. Modern thinkers probably reject the idea that passions can be simple or basic. Rightly, I think.
Apart from pleasure and pain, the only emotions are appetite and aversion [Hobbes]
     Full Idea: All the passions, called passions of the mind, consist of appetite and aversion, except pure pleasure and pain.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 4.25.13)
     A reaction: He now faces the challenge of explaining all the many other emotions in terms of these two. Good luck with that, Thomas.
18. Thought / B. Mechanics of Thought / 5. Mental Files
Words are not for communication, but as marks for remembering what we have learned [Hobbes]
     Full Idea: The use of words consists in this, that they may serve for marks by which whatsoever we have found out may be recalled to memory ...but not as signs by which we declare the same to others.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.11)
     A reaction: This exactly fits the idea of mental files, of which I am a fan. That this is the actual purpose of language is an unusual but interesting view.
19. Language / A. Nature of Meaning / 6. Meaning as Use
Prior to conventions, not all green things were green? [Sider]
     Full Idea: It is absurd to say that 'before we introduced our conventions, not all green things were green'.
     From: Theodore Sider (Writing the Book of the World [2011], 06.5)
     A reaction: Well… Different cultures label the colours of the rainbow differently, and many of them omit orange. I suspect the blue/green borderline has shifted.
19. Language / E. Analyticity / 2. Analytic Truths
Conventions are contingent and analytic truths are necessary, so that isn't their explanation [Sider]
     Full Idea: To suggest that analytic truths make statements about linguistic conventions is a nonstarter; statements about linguistic conventions are contingent, whereas the statements made by typical analytic sentences are necessary.
     From: Theodore Sider (Writing the Book of the World [2011], 06.5)
     A reaction: That 'anything yellow is extended' is not just a convention should be fairly obvious, and it is obviously necessary. But we can say that bachelors are necessarily unmarried men - given the current convention.
19. Language / E. Analyticity / 4. Analytic/Synthetic Critique
Analyticity has lost its traditional role, which relied on truth by convention [Sider]
     Full Idea: Nothing can fully play the role traditionally associated with analyticity, for much of that traditional role presupposed the doctrine of truth by convention.
     From: Theodore Sider (Writing the Book of the World [2011], 09.8)
     A reaction: Sider rejects Quine's attack on analyticity, but accepts his critique of truth by convention.
20. Action / C. Motives for Action / 1. Acting on Desires
The will is just the last appetite before action [Hobbes]
     Full Idea: In deliberation, the last appetite or aversion immediately adhering to the action, or to the omission thereof, is that we call the Will.
     From: Thomas Hobbes (Leviathan [1651], 1.06)
     A reaction: I share his caution about 'the will', but his observation strikes me as inaccurate. When I drink, my 'will' is not my thirst. I take the will to be a feature of my reason. I gave my thirst permission to indulge itself. The will is practical reason?
It is an error that reason should control the passions, which give right guidance on their own [Hobbes, by Tuck]
     Full Idea: Hobbes (and Descartes, and many contemporaries) argued that the traditional idea that reason should control the passions was an error, and that (properly understood) our emotions would guide us in the right direction.
     From: report of Thomas Hobbes (The Elements of Law [1640]) by Richard Tuck - Hobbes Ch.2
     A reaction: I'm an intellectualist on this one. It strikes me as rather naïve and romantic to think that unthinking emotion could ever consistently approach what is right. A recipe for disaster.
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
Reason is usually general, but deliberation is of particulars [Hobbes]
     Full Idea: Reasoning is in general words, but deliberation for the most part is of particulars.
     From: Thomas Hobbes (Leviathan [1651], 1.06)
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / d. Ethical theory
Good and evil are what please us; goodness and badness the powers causing them [Hobbes]
     Full Idea: We call good and evil the things that please and displease us; and so we call goodness and badness, the qualities of powers whereby they do it.
     From: Thomas Hobbes (The Elements of Law [1640], I.7.3), quoted by Richard Tuck - Hobbes Ch.2
     A reaction: It is pointed out by Tuck that this is just like his treatment of colour terms (values as secondary qualities). I would have thought it was obvious that I could say 'x pleases me, although I disapprove of it' (e.g. black humour).
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
'Good' is just what we desire, and 'Evil' what we hate [Hobbes]
     Full Idea: Whatsoever is the object of any man's appetite or desire, that is it which he for his part calleth 'Good'; and the object of his hate or aversion 'Evil'.
     From: Thomas Hobbes (Leviathan [1651], 1.06)
     A reaction: This meets the Frege-Geach Problem - that we can have these feelings while reading ancient history, but we can't possibly 'desire' any of that. This is better on evil than on good.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Self-preservation is basic, and people judge differently about that, implying ethical relativism [Hobbes, by Tuck]
     Full Idea: If men are their own judges of what conduces to their preservation, ..all men make different decisions about what counts as a danger, so (for Hobbes) the grimmest version of ethical relativism seems to be the only possible ethical vision.
     From: report of Thomas Hobbes (The Elements of Law [1640]) by Richard Tuck - Hobbes Ch.2
     A reaction: This might depend on self-preservation being the only fundamental value. But if self-preservation is not a pressing issue, presumably other values might come into play, some of them less concerned with the individual's own interests.
Men's natural desires are no sin, and neither are their actions, until law makes it so [Hobbes]
     Full Idea: The desires and other passions of man are in themselves no sin. No more are the actions that proceed from those passions, till they know a law that forbids them.
     From: Thomas Hobbes (Leviathan [1651], 1.13)
     A reaction: That is a pretty flat rejection of natural law, as you might expect from an empiricist. So prior to the first law-making, no one ever did anything wrong? Hm.
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
There is no absolute good, for even the goodness of God is goodness to us [Hobbes]
     Full Idea: There is no such thing as absolute goodness, considered without relation: for even the goodness which we apprehend in God Almighty, is his goodness to us.
     From: Thomas Hobbes (Human Nature [1640], Ch.VII.3)
     A reaction: Plato's view of goodness is much more absolute than that of religion, as he proposes the Good as the eternal underpinning of nature. I agree with Hobbes that if God is the source of goodness, that will prevent goodness from being truly absolute.
22. Metaethics / B. Value / 2. Values / g. Love
Desire and love are the same, but in the desire the object is absent, and in love it is present [Hobbes]
     Full Idea: Desire and love are the same thing, save that by desire we always signify the absence of the object, by love most commonly the presence of the same.
     From: Thomas Hobbes (Leviathan [1651], 1.06)
     A reaction: Implausible reductivism from Hobbes. Plenty of counterexamples to this. You work it out!
22. Metaethics / B. Value / 2. Values / i. Self-interest
All voluntary acts aim at some good for the doer [Hobbes]
     Full Idea: Of the voluntary acts of every man, the object is some good to himself.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
     A reaction: Nonsense. You can only describe sacrificial acts for loved ones, such as children, in this way if this proposal is a tautology. Hobbes cannot know the truth of this claim.
22. Metaethics / C. The Good / 1. Goodness / c. Right and good
Hobbes shifted from talk of 'the good' to talk of 'rights' [Hobbes, by Tuck]
     Full Idea: Hobbes (like Grotius) shifted from talking about 'the good', which had been the traditional subject for both ancient and Renaissance moralists, to talking instead about 'rights'.
     From: report of Thomas Hobbes (The Elements of Law [1640]) by Richard Tuck - Hobbes Ch.2
     A reaction: This is part of the crucial shift away from the Greek interest in excellence of character, towards the Enlightenment legalistic interest in right actions, as well as social rights. Bad move, well analysed by MacIntyre.
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
Life has no end (not even happiness), because we have desires, which presuppose a further end [Hobbes]
     Full Idea: For an utmost end, in which the ancient philosophers have placed felicity, there is no such thing in this world, nor way to it: for while we live, we have desires, and desire presupposeth a further end.
     From: Thomas Hobbes (Human Nature [1640], Ch.VII.6)
     A reaction: Kant's definition of happiness (Idea 1452) seems to be the underlying idea, and hence with the same implication (of impossibility). However, an alcoholic locked in a brewery would seem to have all that Hobbes requires for happiness.
23. Ethics / B. Contract Ethics / 1. Contractarianism
A contract is a mutual transfer of rights [Hobbes]
     Full Idea: The mutual transferring of right is that which men call 'contract'.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
The person who performs first in a contract is said to 'merit' the return, and is owed it [Hobbes]
     Full Idea: He that performeth first in the case of a contract, is said to 'merit' that which he is to receive by the performance of the other, and he hath it as due.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
Hobbes wants a contract to found morality, but shared values are needed to make a contract [MacIntyre on Hobbes]
     Full Idea: Hobbes makes two incompatible demands of the original contract: he wishes it to be the foundation of all shared and common standards and rules; but he also wishes it to be a contract, which needs prior shared and common standards.
     From: comment on Thomas Hobbes (Leviathan [1651], Pt 1) by Alasdair MacIntyre - A Short History of Ethics Ch.10
     A reaction: At the very least, the participants in a contract must be committed to keeping it even when it is not convenient. But a common purpose seems to be needed too, which makes the contract itself intrinsically valuable. Similar objections to Kant.
23. Ethics / B. Contract Ethics / 2. Golden Rule
For Hobbes the Golden Rule concerns not doing things, whereas Jesus encourages active love [Hobbes, by Flanagan]
     Full Idea: Hobbes put the Golden Rule as 'do NOT do to others what you would NOT want done to yourself'. Jesus's formulation encouraged active love. Most Westerners conceive their moral duty as not to do harm, rather than actively doing good.
     From: report of Thomas Hobbes (Leviathan [1651]) by Owen Flanagan - The Problem of the Soul p.20n
     A reaction: This idea probably runs very deep into western culture, where most people feel that they are being very morally good when they are sitting at home and not actually annoying anyone. Utilitarianism also offers a challenge to such complacency.
23. Ethics / B. Contract Ethics / 3. Promise Keeping
In the violent state of nature, the merest suspicion is enough to justify breaking a contract [Hobbes]
     Full Idea: If a covenant is made with neither party performing presently, but trust one another, in the condition of mere nature (which is war between men) upon reasonable suspicion, it is void.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
23. Ethics / B. Contract Ethics / 4. Value of Authority
Suspicion will not destroy a contract, if there is a common power to enforce it [Hobbes]
     Full Idea: If there be a common power set over both parties in a contract, with right and force sufficient to compel performance, a contract does not become void as soon as the parties are suspicious.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
Fear of sanctions is the only motive for acceptance of authority that Hobbes can think of [MacIntyre on Hobbes]
     Full Idea: Hobbes has such a limited view of human motives that he cannot provide any other explanation for the acceptance of authority than the fear of sanctions..
     From: comment on Thomas Hobbes (Leviathan [1651], Pt 1) by Alasdair MacIntyre - A Short History of Ethics Ch.10
     A reaction: There are two alternative views - the conservative view that people naturally welcome and even need authority, because they need to be led; or the Aristotelian view that people are naturally communal, and authority is part of community life.
23. Ethics / B. Contract Ethics / 5. Free Rider
No one who admitted to not keeping contracts could ever be accepted as a citizen [Hobbes]
     Full Idea: He therefore that breaketh his covenant, and consequently declareth that he thinks he may with reason do so, cannot be received into any society.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
If there is a good reason for breaking a contract, the same reason should have stopped the making of it [Hobbes]
     Full Idea: If any fault of man be sufficient to discharge our covenant made, the same ought in reason to have been sufficient to have hindered the making of it.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
23. Ethics / B. Contract Ethics / 7. Prisoner's Dilemma
The first performer in a contract is handing himself over to an enemy [Hobbes]
     Full Idea: He which performeth first in a contract, does but betray himself to his enemy.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
23. Ethics / B. Contract Ethics / 8. Contract Strategies
Someone who keeps all his contracts when others are breaking them is making himself a prey to others [Hobbes]
     Full Idea: He that should be modest and tractable, and perform all the promises, in such time and place where no man else should do so, should but make himself a prey to others.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Virtues are a means to peaceful, sociable and comfortable living [Hobbes]
     Full Idea: The writers of moral philosophy, though they acknowledge the same virtues and vices, yet not seeing wherein consisted their goodness, nor that they come to be praised as the means of peaceable, sociable and comfortable living.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
Injustice is the failure to keep a contract, and justice is the constant will to give what is owed [Hobbes]
     Full Idea: The definition of 'injustice' is no other than the not performance of covenant….. and 'justice' is the constant will of giving to every man his own.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
24. Political Theory / A. Basis of a State / 1. A People / b. The natural life
In time of war the life of man is solitary, poor, nasty, brutish and short [Hobbes]
     Full Idea: In a time of war…. there is continual fear, and danger of violent death, and the life of man is solitary, poor, nasty, brutish and short.
     From: Thomas Hobbes (Leviathan [1651], 1.13)
Hobbes attributed to savages the passions which arise in a law-bound society [Hobbes, by Rousseau]
     Full Idea: Hobbes had wrongly injected into the savage man's concern for self-preservation the need to satisfy a multitude of passions which are the product of society and which have made laws necessary.
     From: report of Thomas Hobbes (Leviathan [1651]) by Jean-Jacques Rousseau - Discourse on the Origin of Inequality Part I
     A reaction: Hobbes's famous remark concerns a state of war, which is quite a sophisticated state of conflict between well formed social groups. Rousseau's savage is fairly solitary, so won't be involved in war.
24. Political Theory / B. Nature of a State / 2. State Legitimacy / a. Sovereignty
Hobbes says the people voluntarily give up their sovereignty, in a contract with a ruler [Hobbes, by Oksala]
     Full Idea: While Hobbes had held that the people were the final source of political authority, he had argued that in entering the social contract they gave up their sovereignty by transferring all power to an absolute ruler.
     From: report of Thomas Hobbes (Leviathan [1651]) by Johanna Oksala - Political Philosophy: all that matters Ch.5
     A reaction: Later the idea of 'inalienable' rights crept in. If you volunteer for exploitation or slavery, that still doesn't justify them. Sadism is presumably not justified by masochism.
25. Social Practice / B. Equalities / 1. Grounds of equality
There is not enough difference between people for one to claim more benefit than another [Hobbes]
     Full Idea: The difference between man and man is not so considerable as that one man can thereupon claim to himself any benefit to which another may not pretend as well as he.
     From: Thomas Hobbes (Leviathan [1651], 1.13)
Hobbes says people are roughly equal; Locke says there is no right to impose inequality [Hobbes, by Wolff,J]
     Full Idea: Hobbes's principle of equality was a claim about the mental and physical capabilities of all people. For Locke it is a moral claim about rights: no person has a natural right to subordinate any other.
     From: report of Thomas Hobbes (Leviathan [1651]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 1 'Locke'
     A reaction: There are obvious questions to ask about the claim that people are naturally equal. For the second one, does the lion have a natural right to subordinate the gazelle? Who cares! I'm inclined to be consequentialist about equality.
25. Social Practice / C. Rights / 3. Alienating rights
If we seek peace and defend ourselves, we must compromise on our rights [Hobbes]
     Full Idea: From the first law of nature (that we seek peace, but also defend ourselves) comes the second: that a man be willing to lay down his rights to all things, and be contented with so much liberty against other men as he would allow other men against himself.
     From: Thomas Hobbes (Leviathan [1651], 1.14)
25. Social Practice / D. Justice / 2. The Law / c. Natural law
We should obey the laws of nature, provided other people are also obeying them [Hobbes, by Wolff,J]
     Full Idea: Hobbes's position is that we have a duty to obey the Laws of Nature when others around us are known (or can reasonably be expected) to be obeying them too, and so our compliance will not be exploited.
     From: report of Thomas Hobbes (Leviathan [1651]) by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 1 'Hobbes'
     A reaction: In particular, we should keep contracts. Hobbes doesn't seem fully committed to keeping facts and values separate.
25. Social Practice / D. Justice / 2. The Law / d. Legal positivism
The legal positivism of Hobbes said law is just formal or procedural [Hobbes, by Jolley]
     Full Idea: Hobbes was one of the first to propose the view known as 'legal positivism' - that the criterion for deciding whether a rule is a genuine law is entirely formal or procedural
     From: report of Thomas Hobbes (Leviathan [1651]) by Nicholas Jolley - Leibniz Ch.7
     A reaction: This was opposed to the tradition of natural law, deriving from Aquinas. It is part of a picture of values draining out of the world as science comes to dominate. The is/ought distinction is its culmination. Power replaces virtue, and Thrasymachus wins.
25. Social Practice / D. Justice / 3. Punishment / a. Right to punish
Punishment should only be for reform or deterrence [Hobbes]
     Full Idea: We are forbidden to inflict punishment with any other design than for correction of the offender, or direction of others.
     From: Thomas Hobbes (Leviathan [1651], 1.15)
25. Social Practice / E. Policies / 1. War / c. Combatants
I act justly if I follow my Prince in an apparently unjust war, and refusing to fight would be injustice [Hobbes]
     Full Idea: If I wage war at the commandment of my Prince, conceiving the war to be justly undertaken, I do not therefore do unjustly, but rather if I refuse to do it, arrogating to myself the knowledge of what is just and unjust, which pertains only to my Prince.
     From: Thomas Hobbes (De Cive [1642], 12.II), quoted by Jeff McMahan - Killing in War 2.6
     A reaction: Hobbes early says that Princes make things just by commanding them. This presumably assumes divine authority in the Prince. This is, of course, ancient pernicious nonsense.
25. Social Practice / E. Policies / 2. Religion in Society
If fear of unknown powers is legal it is religion, if it is illegal it is superstition [Hobbes]
     Full Idea: Fear of power invisible, feigned by the mind or imagined from tales publicly allowed, is religion; not allowed, is superstition.
     From: Thomas Hobbes (Leviathan [1651], 1.06)
25. Social Practice / F. Life Issues / 5. Sexual Morality
Lust involves pleasure, and also the sense of power in pleasing others [Hobbes]
     Full Idea: Lust consists of two appetites together, to please, and to be pleased, and the delight men take in delighting is not sensual, but a pleasure or joy of the mind consisting in the imagination of the power they have so much to please.
     From: Thomas Hobbes (Human Nature [1640], Ch.IX)
     A reaction: Hobbes would rather burst a blood-vessel than admit any altruism. If you take pleasure in pleasing someone else, why can't that simply be because of the other person's pleasure, with which we sympathise, rather than relishing our own 'power'?
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
Prime matter is body considered with mere size and extension, and potential [Hobbes]
     Full Idea: Prime matter signifies body considered without the consideration of any form or accident except only magnitude or extension, and aptness to receive form and accidents.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.08.24)
     A reaction: I take 'considered without' to indicate that he thinks of it as a psychological abstraction, rather than some actual existing thing.
26. Natural Theory / C. Causation / 1. Causation
Acting on a body is either creating or destroying a property in it [Hobbes]
     Full Idea: A body is said to work upon or act, that is to say, do something to another body, when it either generates or destroys some accident in it.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.09.01)
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
An effect needs a sufficient and necessary cause [Hobbes]
     Full Idea: There can be no effect but from a sufficient and necessary cause.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.10.02)
     A reaction: To be compared with Mackie's subtler modern account of this matter. If two different separate causes could lead to the same result, it is hard to see how the cause must be 'necessary' (unless you say they lead to different effects).
26. Natural Theory / C. Causation / 9. General Causation / a. Constant conjunction
Causation is only observation of similar events following each other, with nothing visible in between [Hobbes]
     Full Idea: In knowing the meaning of 'causing', men can only observe and remember what they have seen to precede the like effect at some other time, without seeing between the antecedent and subsequent event any dependence or connexion at all.
     From: Thomas Hobbes (Leviathan [1651], 1.12)
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
A cause is the complete sum of the features which necessitate the effect [Hobbes]
     Full Idea: A cause it the sum or aggregate of all such accidents, both in the agents and in the patient, as concur to the producing of the effect propounded; all of which existing together, ti cannot be understood but that the effect existenth without them.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.10)
     A reaction: For most causes we meet, this definition will include gravity and electro-magnetism, so it doesn't help in narrowing things down. Notice that he accepts the necessity, despite his committed empiricism.
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
The notion of law doesn't seem to enhance physical theories [Sider]
     Full Idea: Adding the notion of law to physical theory doesn't seem to enhance its explanatory power.
     From: Theodore Sider (Writing the Book of the World [2011], 02.4)
     A reaction: I agree with his scepticism about laws, although Sider offers it as part of his scepticism about modal facts being included in explanations of actuality. Personally I like dispositions, but not laws. See the ideas of Stephen Mumford.
Many of the key theories of modern physics do not appear to be 'laws' [Sider]
     Full Idea: That spacetime is 4D Lorentzian manifold, that the universe began with a singularity, and in a state of low entropy, are all central to physics, but it is a stretch to call them 'laws'. ...It has been argued that there are no laws of biology.
     From: Theodore Sider (Writing the Book of the World [2011], 03.1)
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Motion is losing one place and acquiring another [Hobbes]
     Full Idea: Motion is privation of one place, and the acquisition of another.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 1.6.06)
     A reaction: This is basically the 'at-at' theory of motion which empiricists like, because it breaks motion down into atoms of experience. Hobbes needs an ontology which includes 'places'.
Maybe motion is a dynamical quantity intrinsic to a thing at a particular time [Sider]
     Full Idea: There is an alternative to the Russellian 'at-at' theory of motion, according to which dynamical quantities are intrinsic to times. Whether and how an object is moving at a time is a fact about what that object is like then.
     From: Theodore Sider (Four Dimensionalism [2001], 2.2)
     A reaction: I think I find this quite appealing, because there is too much of a tendency to think of objects as passive and inert, with laws, forces, motions etc. imposed from the outside. But nature is active and dynamic. However, motion can't be wholly intrinsic.
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
'Force' is the quantity of movement imposed on something [Hobbes]
     Full Idea: I define 'force' to be the impetus or quickness of motion multiplied either into itself, or into the magnitude of the movent, by means of which whereof the said movent works more or less upon the body that resists it.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 3.15.02)
     A reaction: Not very helpful, perhaps, but it shows a view of force at quite an early date, well before Newton.
27. Natural Reality / C. Space / 4. Substantival Space
Space has real betweenness and congruence structure (though it is not the Euclidean concepts) [Sider]
     Full Idea: In metaphysics, space is intrinsically structured; the genuine betweenness and congruence relations are privileged in a way that Euclidean-betweenness and Euclidean-congruence are not.
     From: Theodore Sider (Writing the Book of the World [2011], 03.4)
     A reaction: I note that Einstein requires space to be 'curved', which implies that it is a substance with properties.
27. Natural Reality / C. Space / 6. Space-Time
Space is 3D and lacks a direction; time seems connected to causation [Sider]
     Full Idea: Unlike time, space has three dimensions and lacks a distinguishing direction; unlike space, time seems to be specially connected with causation.
     From: Theodore Sider (Four Dimensionalism [2001], 4.5)
     A reaction: These strike me as nice reasons to doubt (what I already prima facie doubt) that there is a single manifold that is 'space-time', for all that twentieth century physics tells us it is so. A century is a mere click of a clock where truth is concerned.
The central question in the philosophy of time is: How alike are time and space? [Sider]
     Full Idea: The central question in the philosophy of time is: How alike are time and space?
     From: Theodore Sider (Writing the Book of the World [2011], 11.1)
27. Natural Reality / D. Time / 1. Nature of Time / f. Eternalism
The spotlight theorists accepts eternal time, but with a spotlight of the present moving across it [Sider]
     Full Idea: The spotlight theorist accepts the block universe, but also something in addition: a joint-carving monadic property of presentness, which is possessed by just one moment of time, and which 'moves', to be possessed by later and later times.
     From: Theodore Sider (Writing the Book of the World [2011], 11.9)
     A reaction: This seems better than the merely detached eternalist view, which seems to ignore the key phenomenon. I just can't comprehend any theory which makes the future as real as the past.
27. Natural Reality / D. Time / 1. Nature of Time / g. Growing block
Between presentism and eternalism is the 'growing block' view - the past is real, the future is not [Sider]
     Full Idea: Intermediate between the polar opposites of presentism and eternalism is the view (defended by Broad 1923 and Tooley 1997) that the past is real but the future is not. Reality consists of a growing four-dimensional manifold, the 'growing block universe'.
     From: Theodore Sider (Four Dimensionalism [2001], 2.1)
     A reaction: The obvious and plausible basis for this is that statements about the past seem to have truthmakers, but statements about the future lack them. Does a truth always require ontological commitment? Death is cessation of existence.
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
For Presentists there must always be a temporal vantage point for any description [Sider]
     Full Idea: The Presentist acknowledges that no atemporal description of the case can be given; a vantage point must be chosen for any description.
     From: Theodore Sider (Four Dimensionalism [2001], 5.5)
     A reaction: This is because Presentists are committed to tense, which have to be either explicit or implicit in any sentence. But what of famously 'timeless' truths such as '2 and 2 are 4'?
Presentists must deny truths about multiple times [Sider]
     Full Idea: The presentist must deny the truth of everyday claims that concern multiple times taken together.
     From: Theodore Sider (Four Dimensionalism [2001], 2.2)
     A reaction: This rests on the extent to which every truth has an ontological commitment. You can deny the literal existence of multiple times without denying such truths.
27. Natural Reality / D. Time / 2. Passage of Time / c. Tenses and time
Talk using tenses can be eliminated, by reducing it to indexical connections for an utterance [Sider]
     Full Idea: The temporal reductionist claims that tensed locutions are indexical - 'present' being the time of utterance etc. This generalises to say that nothing corresponding to tense need be admitted as a fundamental feature of the world.
     From: Theodore Sider (Four Dimensionalism [2001], 2.1)
     A reaction: [He particular cites Mellor for this view] Highly implausible. I very much doubt whether it is possible to explain the indexicality of a word like 'now' without referring to tenses. Does time only exist when sentences and thoughts occur?
27. Natural Reality / D. Time / 2. Passage of Time / f. Tenseless (B) series
The B-theory is adequate, except that it omits to say which time is present [Sider]
     Full Idea: The B-theoretic description of the world is completely adequate except that it leaves out information about which time is present.
     From: Theodore Sider (Four Dimensionalism [2001], 4.6)
     A reaction: This strikes me as a pretty basic deficiency. How could there a time which lacked a present moment? The present is when things happen. How would it qualify as time at all if it lacked past, present and future?
The B-series involves eternalism, and the reduction of tense [Sider]
     Full Idea: The B-series has two components: eternalism - the thesis that all future entities are real - and the thesis of reducibility of tense.
     From: Theodore Sider (Four Dimensionalism [2001], 4.2)
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
Past times can't exist anywhere, apart from in our memories [Hobbes]
     Full Idea: When people speak of the times of their predecessors, they do not think after their predecessors are gone that their times can be any where else than in the memory of those that remember.
     From: Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.07.03)
28. God / C. Attitudes to God / 4. God Reflects Humanity
The attributes of God just show our inability to conceive his nature [Hobbes]
     Full Idea: All the attributes of God signify our inability and defect of power to conceive any thing concerning his nature.
     From: Thomas Hobbes (The Elements of Law [1640], I.10.2), quoted by Richard Tuck - Hobbes Ch.2
     A reaction: Presumably he means that 'omnipotence' should just be translated as 'mind-boggling power'. St Anselm's concept of God (Idea 1405) is helpful here, placing it at the upper limit of what can actually be conceived.
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
Religion is built on ignorance and misinterpretation of what is unknown or frightening [Hobbes]
     Full Idea: In these four things - opinion of ghosts, ignorance of second causes, devotion towards what men fear, and taking of things casual for prognostics, consisteth the natural seed of religion.
     From: Thomas Hobbes (Leviathan [1651], 1.12)
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Belief in an afterlife is based on poorly founded gossip [Hobbes]
     Full Idea: Knowledge of man's estate after death, and its rewards, is a belief grounded upon other men's sayings that they knew it supernaturally, or they knew those, that knew those, that knew others, that knew it supernaturally.
     From: Thomas Hobbes (Leviathan [1651], 1.15)