112 ideas
19693 | There is practical wisdom (for action), and theoretical wisdom (for deep understanding) [Aristotle, by Whitcomb] |
Full Idea: Aristotle takes wisdom to come in two forms, the practical and the theoretical, the former of which is good judgement about how to act, and the latter of which is deep knowledge or understanding. | |
From: report of Aristotle (works [c.330 BCE]) by Dennis Whitcomb - Wisdom Intro | |
A reaction: The interesting question is then whether the two are connected. One might be thoroughly 'sensible' about action, without counting as 'wise', which seems to require a broader view of what is being done. Whitcomb endorses Aristotle on this idea. |
1575 | For Aristotle logos is essentially the ability to talk rationally about questions of value [Roochnik on Aristotle] |
Full Idea: For Aristotle logos is the ability to speak rationally about, with the hope of attaining knowledge, questions of value. | |
From: comment on Aristotle (works [c.330 BCE]) by David Roochnik - The Tragedy of Reason p.26 |
1589 | Aristotle is the supreme optimist about the ability of logos to explain nature [Roochnik on Aristotle] |
Full Idea: Aristotle is the great theoretician who articulates a vision of a world in which natural and stable structures can be rationally discovered. His is the most optimistic and richest view of the possibilities of logos | |
From: comment on Aristotle (works [c.330 BCE]) by David Roochnik - The Tragedy of Reason p.95 |
8200 | Aristotelian definitions aim to give the essential properties of the thing defined [Aristotle, by Quine] |
Full Idea: A real definition, according to the Aristotelian tradition, gives the essence of the kind of thing defined. Man is defined as a rational animal, and thus rationality and animality are of the essence of each of us. | |
From: report of Aristotle (works [c.330 BCE]) by Willard Quine - Vagaries of Definition p.51 | |
A reaction: Compare Idea 4385. Personally I prefer the Aristotelian approach, but we may have to say 'We cannot identify the essence of x, and so x cannot be defined'. Compare 'his mood was hard to define' with 'his mood was hostile'. |
4385 | Aristotelian definition involves first stating the genus, then the differentia of the thing [Aristotle, by Urmson] |
Full Idea: For Aristotle, to give a definition one must first state the genus and then the differentia of the kind of thing to be defined. | |
From: report of Aristotle (works [c.330 BCE]) by J.O. Urmson - Aristotle's Doctrine of the Mean p.157 | |
A reaction: Presumably a modern definition would just be a list of properties, but Aristotle seeks the substance. How does he define a genus? - by placing it in a further genus? |
13689 | '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) |
13705 | 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) |
13706 | 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) |
13710 | 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) |
13711 | 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) |
13708 | 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. |
13712 | 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) |
13714 | 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) |
13720 | 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. |
13718 | 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. |
13723 | 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) |
13715 | 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. |
13282 | Aristotle relativises the notion of wholeness to different measures [Aristotle, by Koslicki] |
Full Idea: Aristotle proposes to relativise unity and plurality, so that a single object can be both one (indivisible) and many (divisible) simultaneously, without contradiction, relative to different measures. Wholeness has degrees, with the strength of the unity. | |
From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 7.2.12 | |
A reaction: [see Koslicki's account of Aristotle for details] As always, the Aristotelian approach looks by far the most promising. Simplistic mechanical accounts of how parts make wholes aren't going to work. We must include the conventional and conceptual bit. |
13678 | 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. |
13682 | 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. |
13680 | 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. |
13679 | 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. |
13722 | 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. |
4730 | For Aristotle, the subject-predicate structure of Greek reflected a substance-accident structure of reality [Aristotle, by O'Grady] |
Full Idea: Aristotle apparently believed that the subject-predicate structure of Greek reflected the substance-accident nature of reality. | |
From: report of Aristotle (works [c.330 BCE]) by Paul O'Grady - Relativism Ch.4 | |
A reaction: We need not assume that Aristotle is wrong. It is a chicken-and-egg. There is something obvious about subject-predicate language, if one assumes that unified objects are part of nature, and not just conventional. |
13696 | 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) |
13700 | 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) |
4098 | The theory of descriptions supports internalism, since they are thinkable when the object is non-existent [Crane] |
Full Idea: The theory of descriptions gives a model of internalist intentionality, in that it describes cases where the thinkability of a belief does not depend on the existence of a specific object. | |
From: Tim Crane (Elements of Mind [2001], 4.36) | |
A reaction: So what do externalists say about the theory? Surely a reference to 'water' can't entail the existence of water? |
13703 | 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) |
13688 | 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) |
13687 | 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. |
13691 | 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] |
13690 | 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. |
13685 | 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. |
13686 | 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. |
13697 | 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. |
13684 | 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. |
13704 | 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. |
13724 | 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) |
13698 | 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). |
13699 | 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) |
13701 | 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) |
4077 | Aesthetic properties of thing supervene on their physical properties [Crane] |
Full Idea: It is sometimes said that the aesthetic properties of a thing supervene on its physical properties. | |
From: Tim Crane (Elements of Mind [2001], 2.16) | |
A reaction: A confusing example, as aesthetic properties only exist if there is an observer. Is 'supervenience' just an empty locution which tries to avoid reduction? |
4078 | Constitution (as in a statue constituted by its marble) is supervenience without identity [Crane] |
Full Idea: A statue is constituted by the marble that makes it up. It is plausible to say that constitution is not the same as identity - since identity is symmetrical and identity is not - but nonetheless constitution is a supervenience relation. | |
From: Tim Crane (Elements of Mind [2001], 2.16) | |
A reaction: So what makes it a statue, as opposed to a piece of marble? It may well be an abstraction which only exists relative to observers. |
13692 | 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] |
13693 | 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. |
13695 | 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) |
13694 | 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. |
13683 | 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. |
4082 | The distinction between 'resultant' properties (weight) and 'emergent' properties is a bit vague [Crane] |
Full Idea: The distinction between 'resultant' properties like weight, and 'emergent' properties like colour, seems intuitive enough, but on examination it is very hard to make precise. | |
From: Tim Crane (Elements of Mind [2001], 2.18) | |
A reaction: It is no coincidence that the examples are of primary and secondary qualities. If 'the physical entails the mental' then all mental properties are resultant. |
4083 | If mental properties are emergent they add a new type of causation, and physics is not complete [Crane] |
Full Idea: Whatever the causal process is, it remains true that if emergentism is true, the completeness of physics is false; there are some effects which would not have come about if mental things were absent from the world. | |
From: Tim Crane (Elements of Mind [2001], 2.18) | |
A reaction: Emergentism looks to me like an incoherent concept, unless it is another word for dualism. |
4079 | Properties are causes [Crane] |
Full Idea: Properties are causes. | |
From: Tim Crane (Elements of Mind [2001], 2.17) | |
A reaction: We can't detect properties if they lack causal powers. This may be a deep confusion. Properties are what make causal powers possible, but that isn't what properties are? |
4068 | Traditional substance is separate from properties and capable of independent existence [Crane] |
Full Idea: The traditional concept of substance says substances bear properties which are distinct from them, and substances are capable of independent existence. | |
From: Tim Crane (Elements of Mind [2001], 2.9) | |
A reaction: Put like that, it sounds ridiculous as a physical theory. It is hard to dislodge substance, though, from a priori human metaphysics. |
13276 | The unmoved mover and the soul show Aristotelian form as the ultimate mereological atom [Aristotle, by Koslicki] |
Full Idea: Aristotle's discussion of the unmoved mover and of the soul confirms the suspicion that form, when it is not thought of as the object represented in a definition, plays the role of the ultimate mereological atom within his system. | |
From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 6.6 | |
A reaction: Aristotle is concerned with which things are 'divisible', and he cites these two examples as indivisible, but they may be too unusual to offer an actual theory of how Aristotle builds up wholes from atoms. He denies atoms in matter. |
13277 | The 'form' is the recipe for building wholes of a particular kind [Aristotle, by Koslicki] |
Full Idea: Thus in Aristotle we may think of an object's formal components as a sort of recipe for how to build wholes of that particular kind. | |
From: report of Aristotle (works [c.330 BCE]) by Kathrin Koslicki - The Structure of Objects 7.2.5 | |
A reaction: In the elusive business of pinning down what Aristotle means by the crucial idea of 'form', this analogy strikes me as being quite illuminating. It would fit DNA in living things, and the design of an artifact. |
13702 | 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. |
13721 | '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. |
13707 | 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! |
13709 | 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) |
13716 | '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? |
13717 | 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? |
13719 | 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. |
5991 | For Aristotle, knowledge is of causes, and is theoretical, practical or productive [Aristotle, by Code] |
Full Idea: Aristotle thinks that in general we have knowledge or understanding when we grasp causes, and he distinguishes three fundamental types of knowledge - theoretical, practical and productive. | |
From: report of Aristotle (works [c.330 BCE]) by Alan D. Code - Aristotle | |
A reaction: Productive knowledge we tend to label as 'knowing how'. The centrality of causes for knowledge would get Aristotle nowadays labelled as a 'naturalist'. It is hard to disagree with his three types, though they may overlap. |
4097 | Maybe there are two kinds of belief - 'de re' beliefs and 'de dicto' beliefs [Crane] |
Full Idea: Some philosophers have claimed that there are two kinds of belief, 'de re' belief and 'de dicto' belief. | |
From: Tim Crane (Elements of Mind [2001], 4.35) | |
A reaction: Interesting, though it may only distinguish two objects of belief, not two types. Internalist and externalist views are implied. |
4096 | Maybe beliefs don't need to be conscious, if you are not conscious of the beliefs guiding your actions [Crane] |
Full Idea: The beliefs that are currently guiding your actions do not need to be in your stream of consciousness, which suggests that beliefs do not need to be conscious at all. | |
From: Tim Crane (Elements of Mind [2001], 4.31) | |
A reaction: Too bold, I think. Presumably this would eliminate all the other propositional attitudes from consciousness. There would only be qualia left! |
4093 | Many cases of knowing how can be expressed in propositional terms (like how to get somewhere) [Crane] |
Full Idea: There are plenty of cases of knowing how to do something, where that knowledge can also be expressed - without remainder, as it were - in propositional terms (such as knowing how to get to the Albert Hall). | |
From: Tim Crane (Elements of Mind [2001], 3.28) | |
A reaction: Presumably all knowing how could be expressed propositionally by God. |
11239 | The notion of a priori truth is absent in Aristotle [Aristotle, by Politis] |
Full Idea: The notion of a priori truth is conspicuously absent in Aristotle. | |
From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.5 | |
A reaction: Cf. Idea 11240. |
4108 | Phenol-thio-urea tastes bitter to three-quarters of people, but to the rest it is tasteless, so which is it? [Crane] |
Full Idea: Phenol-thio-urea tastes bitter to three-quarters of people, but to the rest it is tasteless. Is it really bitter, or really tasteless? | |
From: Tim Crane (Elements of Mind [2001], 5.44) | |
A reaction: A nice reinforcement of a classic Greek question. Good support for the primary/secondary distinction. Common sense, really. |
4105 | The traditional supports for the sense datum theory were seeing double and specks before one's eyes [Crane] |
Full Idea: The traditional examples used to support the sense datum theory were seeing double and specks before one's eyes. | |
From: Tim Crane (Elements of Mind [2001], 5.43) | |
A reaction: Presumably, though, direct realists can move one eye, or having something wrong with a retina. |
4104 | One can taste that the wine is sour, and one can also taste the sourness of the wine [Crane] |
Full Idea: One can taste that the wine is sour, and one can also taste the sourness of the wine. | |
From: Tim Crane (Elements of Mind [2001], 5.42) | |
A reaction: …so sense data are optional? We create sense data by objectifying them, but animals just taste the wine, and are direct realists. Tasting the sourness seems to be a case of abstraction. |
4101 | If we smell something we are aware of the smell separately, but we don't perceive a 'look' when we see [Crane] |
Full Idea: Visual perception seems to differ from some of the other senses; when we become aware of burning toast, we become aware of the smell, ...but we don't see a garden by seeing a 'look' of the garden. | |
From: Tim Crane (Elements of Mind [2001], 5.40) | |
A reaction: Interesting. Do blind people transfer this more direct perception to a different sense (e.g. the one they rely on most)? |
4102 | The problems of perception disappear if it is a relation to an intentional state, not to an object or sense datum [Crane] |
Full Idea: The solution to the problem of perception is to deny that it is related to real objects (things or sense-data); rather, perception is an intentional state (with a subject, mode and content), a relation to the intentional content. | |
From: Tim Crane (Elements of Mind [2001], 5.42) | |
A reaction: Not clear. This definition makes it sound like a propositional attitude. |
4109 | If perception is much richer than our powers of description, this suggests that it is non-conceptual [Crane] |
Full Idea: The richness in information of perceptual experience outruns our modes of description of it, which has led some philosophers to claim that the content of perceptual experience is non-conceptual. | |
From: Tim Crane (Elements of Mind [2001], 5.45) | |
A reaction: It certainly implies that it can't be entirely conceptual, but it still may be that in humans concepts are always involved. Not when I'm waking up in the morning, though. |
4103 | The adverbial theory of perceptions says it is the experiences which have properties, not the objects [Crane] |
Full Idea: The Adverbial Theory of perception holds that the predicates which other theories take as picking out the properties of objects are really adverbs of the perceptual verb; ..instead of strange objects, we just have properties of experiences. | |
From: Tim Crane (Elements of Mind [2001], 5.42) | |
A reaction: Promising. It fits secondary qualities all right, but what about primary? I 'see bluely', but can I 'see squarely'? |
23312 | Aristotle is a rationalist, but reason is slowly acquired through perception and experience [Aristotle, by Frede,M] |
Full Idea: Aristotle is a rationalist …but reason for him is a disposition which we only acquire over time. Its acquisition is made possible primarily by perception and experience. | |
From: report of Aristotle (works [c.330 BCE]) by Michael Frede - Aristotle's Rationalism p.173 | |
A reaction: I would describe this process as the gradual acquisition of the skill of objectivity, which needs the right knowledge and concepts to evaluate new experiences. |
16111 | Aristotle wants to fit common intuitions, and therefore uses language as a guide [Aristotle, by Gill,ML] |
Full Idea: Since Aristotle generally prefers a metaphysical theory that accords with common intuitions, he frequently relies on facts about language to guide his metaphysical claims. | |
From: report of Aristotle (works [c.330 BCE]) by Mary Louise Gill - Aristotle on Substance Ch.5 | |
A reaction: I approve of his procedure. I take intuition to be largely rational justifications too complex for us to enunciate fully, and language embodies folk intuitions in its concepts (especially if the concepts occur in many languages). |
4065 | Is knowledge just a state of mind, or does it also involve the existence of external things? [Crane] |
Full Idea: It is controversial whether knowledge is a state of mind, or a composite state involving a thought about something, plus its existence. | |
From: Tim Crane (Elements of Mind [2001], 1.5) | |
A reaction: Pinpoints the internalism/externalism problem. Knowledge is a special type of belief (but maybe belief with external links!). Tricky. I vote for internalism. |
16971 | Plato says sciences are unified around Forms; Aristotle says they're unified around substance [Aristotle, by Moravcsik] |
Full Idea: Plato's unity of science principle states that all - legitimate - sciences are ultimately about the Forms. Aristotle's principle states that all sciences must be, ultimately, about substances, or aspects of substances. | |
From: report of Aristotle (works [c.330 BCE], 1) by Julius Moravcsik - Aristotle on Adequate Explanations 1 |
11243 | Aristotelian explanations are facts, while modern explanations depend on human conceptions [Aristotle, by Politis] |
Full Idea: For Aristotle things which explain (the explanantia) are facts, which should not be associated with the modern view that says explanations are dependent on how we conceive and describe the world (where causes are independent of us). | |
From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 2.1 | |
A reaction: There must be some room in modern thought for the Aristotelian view, if some sort of robust scientific realism is being maintained against the highly linguistic view of philosophy found in the twentieth century. |
3320 | Aristotle's standard analysis of species and genus involves specifying things in terms of something more general [Aristotle, by Benardete,JA] |
Full Idea: The standard Aristotelian doctrine of species and genus in the theory of anything whatever involves specifying what the thing is in terms of something more general. | |
From: report of Aristotle (works [c.330 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.10 |
12000 | Aristotle regularly says that essential properties explain other significant properties [Aristotle, by Kung] |
Full Idea: The view that essential properties are those in virtue of which other significant properties of the subjects under investigation can be explained is encountered repeatedly in Aristotle's work. | |
From: report of Aristotle (works [c.330 BCE]) by Joan Kung - Aristotle on Essence and Explanation IV | |
A reaction: What does 'significant' mean here? I take it that the significant properties are the ones which explain the role, function and powers of the object. |
4092 | The core of the consciousness problem is the case of Mary, zombies, and the Hard Question [Crane] |
Full Idea: The three arguments that have been used to articulate the problem of consciousness are the knowledge argument ('Mary'), the possibility of 'zombies' (creatures like us but lacking phenomenal consciousness), and the explanatory gap (the Hard Question). | |
From: Tim Crane (Elements of Mind [2001], 3.26) | |
A reaction: All of these push towards the implausible claim that there could never be a physical explanation of why we experience things. Zombies are impossible, in my opinion. |
4087 | Intentionalism does not require that all mental states be propositional attitudes [Crane] |
Full Idea: Intentionalism (the doctrine that all mental states are intentional) need not be the thesis that all mental states are propositional attitudes. | |
From: Tim Crane (Elements of Mind [2001], 3.22) | |
A reaction: This points to the requirement for an intentionalist to prove that so-called 'qualia' states are essentially intentional, which is not implausible. |
4095 | Object-directed attitudes like love are just as significant as propositional attitudes [Crane] |
Full Idea: Love, hate, and the other object-directed attitudes have as much of a role in explaining behaviour as the propositional attitudes. | |
From: Tim Crane (Elements of Mind [2001], 4.34) | |
A reaction: A good clarification of the range of intentional states. Objects seem to be external, where propositions are clearly internal. |
4106 | If someone removes their glasses the content of experience remains, but the quality changes [Crane] |
Full Idea: There is a phenomenal difference between a short-sighted person wearing glasses and not; they do not judge that the world is different, but the properties of the experience (the qualia) have changed. | |
From: Tim Crane (Elements of Mind [2001], 5.43) | |
A reaction: Could be challenged. If a notice becomes unreadable, that is more than the qualia changing. |
4089 | Pains have a region of the body as their intentional content, not some pain object [Crane] |
Full Idea: The intentional object of a pain-state is a part or region of the body, not a pain-object. | |
From: Tim Crane (Elements of Mind [2001], 3.24) | |
A reaction: Plausible. Has anyone ever suffered from pain without some sense of what part of the body is actually in pain? |
4090 | Weak intentionalism says qualia are extra properties; strong intentionalism says they are intentional [Crane] |
Full Idea: Weak intentionalism says all mental states are intentional, but qualia are higher-order properties of these states. ..Strong intentionalists say the phenomenal character of a sensation consists purely in that state's intentionality. | |
From: Tim Crane (Elements of Mind [2001], 3.25) | |
A reaction: The weak version sounds better. Asking 'how could a thought have a quality of experience just by being about something?' is a restatement of the traditional problem, which won't go away. The Hard Question. |
4107 | With inverted qualia a person's experiences would change, but their beliefs remain the same [Crane] |
Full Idea: The right thing to say about inverted qualia is that the person's experiences are different from other people's, but their beliefs are the same. | |
From: Tim Crane (Elements of Mind [2001], 5.44) | |
A reaction: Right - which reinforces the idea that all beliefs are the result of judgement, and none come directly from perception. |
4069 | Descartes did not think of minds as made of a substance, because they are not divisible [Crane] |
Full Idea: It would be wrong to represent Descartes' view as the idea that bodies are made of one kind of stuff and minds of another; he did not think minds are made of stuff at all, because then they would be divisible. | |
From: Tim Crane (Elements of Mind [2001], 2.10) | |
A reaction: I'm not convinced. It could be an indivisible substance. Without a mental substance, Descartes may have to say the mind is an abstraction, perhaps a pattern of Platonic forms. |
4074 | Functionalism defines mental states by their causal properties, which rules out epiphenomenalism [Crane] |
Full Idea: Functionalism holds that it is in the nature of certain mental states to have certain effects; therefore there can be no mental epiphenomena. | |
From: Tim Crane (Elements of Mind [2001], 2.14) | |
A reaction: I strongly resist the idea that a thing's identity is its function. Functionalism may not say that. Mind is an abstraction referring to a causal nexus of unknowable components. |
4091 | The problems of misrepresentation and error have dogged physicalist reductions of intentionality [Crane] |
Full Idea: The fundamental problems of misrepresentation and error have dogged physicalist reductions of intentionality. | |
From: Tim Crane (Elements of Mind [2001], 3.26) | |
A reaction: If footprints or tree-rings are the model for reductions of intentionality, there doesn't seem much scope in them for giving false information, except by some freak event. |
4070 | Properties dualism says mental properties are distinct from physical, despite a single underlying substance [Crane] |
Full Idea: According to property dualism, mental properties are distinct from physical properties, even though they are properties of one substance. | |
From: Tim Crane (Elements of Mind [2001], 2.10) | |
A reaction: Two properties may be phenomenologically different (transparent and magnetic), but that doesn't put them in different ontological categories. |
4084 | Non-reductive physicalism seeks an explanation of supervenience, but emergentists accept it as basic [Crane] |
Full Idea: While the non-reductive physicalist believes that mental/physical supervenience must be explained, the emergentist is willing to accept it as a fact of nature. | |
From: Tim Crane (Elements of Mind [2001], 2.18) | |
A reaction: A good reason not to be an emergentist. No philosopher should abandon the principle of sufficient reason. |
4080 | If mental supervenes on the physical, then every physical cause will be accompanied by a mental one [Crane] |
Full Idea: If the mental supervenes on the physical, then whenever a physical cause brings about some effect, a mental cause comes along for the ride. | |
From: Tim Crane (Elements of Mind [2001], 2.17) | |
A reaction: This is why supervenience seems to imply epiphenomenalism. The very concept of supervenience is dubious. |
4085 | Physicalism may be the source of the mind-body problem, rather than its solution [Crane] |
Full Idea: Physicalism may be the source of the mind-body problem, rather than its solution. | |
From: Tim Crane (Elements of Mind [2001], 2.19) | |
A reaction: Certainly if the physical is seen as just a pile of atoms, it is hard to see how they could ever think (see idea 1909). |
4075 | Identity theory is either of particular events, or of properties, depending on your theory of causation [Crane] |
Full Idea: If causation concerns events, then we have an identity theory of mental and physical events (particulars) [Davidson]. If causation is by properties, then it is mental and physical properties which are identical [Lewis and Armstrong]. | |
From: Tim Crane (Elements of Mind [2001], 2.14) | |
A reaction: Events are tokens, and properties are types. Tricky. Events are dynamic, but properties can be static. |
4073 | Overdetermination occurs if two events cause an effect, when each would have caused it alone [Crane] |
Full Idea: Causal overdetermination is when an effect has more than one cause, and each event would have caused the effect if the other one had not done so. | |
From: Tim Crane (Elements of Mind [2001], 2.13) | |
A reaction: Overdetermination is a symptom that an explanation is questionable, but it can occur. Two strong people can join to push over a light hatstand. |
4072 | The completeness of physics must be an essential component of any physicalist view of mind [Crane] |
Full Idea: I claim that the completeness of physics must be an essential component of any physicalist view of mind. | |
From: Tim Crane (Elements of Mind [2001], 2.12) | |
A reaction: He does not convince me of this. The mind may be within physics, but why should we say a priori that no exceptions to physical law will ever be discovered. Crane is setting up straw men. |
4094 | Experience teaches us propositions, because we can reason about our phenomenal experience [Crane] |
Full Idea: In experience we learn propositions, since someone can reason using the sentence 'Red looks like this' (e.g. 'If red looks like this, then either it looks like this to dogs or it doesn't'). | |
From: Tim Crane (Elements of Mind [2001], 3.28) | |
A reaction: The fact that we can create propositions about experiences doesn't prove that experience is inherently propositional. |
23300 | Aristotle and the Stoics denied rationality to animals, while Platonists affirmed it [Aristotle, by Sorabji] |
Full Idea: Aristotle, and also the Stoics, denied rationality to animals. …The Platonists, the Pythagoreans, and some more independent Aristotelians, did grant reason and intellect to animals. | |
From: report of Aristotle (works [c.330 BCE]) by Richard Sorabji - Rationality 'Denial' | |
A reaction: This is not the same as affirming or denying their consciousness. The debate depends on how rationality is conceived. |
4100 | The Twin Earth argument depends on reference being determined by content, which may be false. [Crane] |
Full Idea: The Twin Earth argument does not refute internalism, since it depends on the 'Content-Determines-Reference' principle, which internalists can reject. | |
From: Tim Crane (Elements of Mind [2001], 4.37) | |
A reaction: The idea is that content should be understood in a context (e.g. on a particular planet). Indexicals count against a totally narrow view of content (Twins thinking 'I am here'). |
4067 | Broad content entails the existence of the object of the thought [Crane] |
Full Idea: If a mental state is broad, then the existence of the mental state entails the existence of its object. | |
From: Tim Crane (Elements of Mind [2001], 1.7) | |
A reaction: Hence thinking of non-existent things like unicorns is problematic for externalists. However, externalists can think about numbers or Platonic ideals. |
4063 | In intensional contexts, truth depends on how extensions are conceived. [Crane] |
Full Idea: Intensional contexts are those where truth or falsehood depends on the way the extensions are conceived. | |
From: Tim Crane (Elements of Mind [2001], 1.4) | |
A reaction: An important distinction for anyone defending an internalist view of concepts or of knowledge |
11240 | The notion of analytic truth is absent in Aristotle [Aristotle, by Politis] |
Full Idea: The notion of analytic truth is conspicuously absent in Aristotle. | |
From: report of Aristotle (works [c.330 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.5 | |
A reaction: Cf. Idea 11239. |
6559 | Aristotle never actually says that man is a rational animal [Aristotle, by Fogelin] |
Full Idea: To the best of my knowledge (and somewhat to my surprise), Aristotle never actually says that man is a rational animal; however, he all but says it. | |
From: report of Aristotle (works [c.330 BCE]) by Robert Fogelin - Walking the Tightrope of Reason Ch.1 | |
A reaction: When I read this I thought that this database would prove Fogelin wrong, but it actually supports him, as I can't find it in Aristotle either. Descartes refers to it in Med.Two. In Idea 5133 Aristotle does say that man is a 'social being'. But 22586! |
11150 | It is the mark of an educated mind to be able to entertain an idea without accepting it [Aristotle] |
Full Idea: It is the mark of an educated mind to be able to entertain an idea without accepting it. | |
From: Aristotle (works [c.330 BCE]) | |
A reaction: The epigraph on a David Chalmers website. A wonderful remark, and it should be on the wall of every beginners' philosophy class. However, while it is in the spirit of Aristotle, it appears to be a misattribution with no ancient provenance. |
3037 | Aristotle said the educated were superior to the uneducated as the living are to the dead [Aristotle, by Diog. Laertius] |
Full Idea: Aristotle was asked how much educated men were superior to those uneducated; "As much," he said, "as the living are to the dead." | |
From: report of Aristotle (works [c.330 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 05.1.11 |
8660 | There are potential infinities (never running out), but actual infinity is incoherent [Aristotle, by Friend] |
Full Idea: Aristotle developed his own distinction between potential infinity (never running out) and actual infinity (there being a collection of an actual infinite number of things, such as places, times, objects). He decided that actual infinity was incoherent. | |
From: report of Aristotle (works [c.330 BCE]) by Michčle Friend - Introducing the Philosophy of Mathematics 1.3 | |
A reaction: Friend argues, plausibly, that this won't do, since potential infinity doesn't make much sense if there is not an actual infinity of things to supply the demand. It seems to just illustrate how boggling and uncongenial infinity was to Aristotle. |
12058 | Aristotle's matter can become any other kind of matter [Aristotle, by Wiggins] |
Full Idea: Aristotle's conception of matter permits any kind of matter to become any other kind of matter. | |
From: report of Aristotle (works [c.330 BCE]) by David Wiggins - Substance 4.11.2 | |
A reaction: This is obviously crucial background information when we read Aristotle on matter. Our 92+ elements, and fixed fundamental particles, gives a quite different picture. Aristotle would discuss form and matter quite differently now. |
4071 | Causation can be seen in counterfactual terms, or as increased probability, or as energy flow [Crane] |
Full Idea: A theory of causation might say 'If A had not existed, B would not have existed' (counterfactual theory), or 'B is more likely if A occurs' (probabilistic), or 'energy flows from A to B'. | |
From: Tim Crane (Elements of Mind [2001], 2.11) | |
A reaction: As always, it is vital to separate epistemology from ontology. Energy won't cover agents. Whisper "Fire!" in a theatre. |
4076 | Causes are properties, not events, because properties are what make a difference in a situation [Crane] |
Full Idea: My view is that causes are properties (not events); when we look for causes, we look for the aspect of a situation which made a difference, and aspects are properties or qualities. | |
From: Tim Crane (Elements of Mind [2001], 2.14) | |
A reaction: He is talking about explanations, which may not be causes, or at least they have a different emphasis. Don't events 'make a difference'? Events are ontologically weird |
4066 | It seems that 'exists' could sometimes be a predicate [Crane] |
Full Idea: The view that 'exists' is never a predicate is not plausible. | |
From: Tim Crane (Elements of Mind [2001], 1.7) | |
A reaction: He doesn't enlarge. Russell says 'exists' is a quantifier. 'Your very existence offends me - I hope it is confiscated'. |
22729 | The concepts of gods arose from observing the soul, and the cosmos [Aristotle, by Sext.Empiricus] |
Full Idea: Aristotle said that the conception of gods arose among mankind from two originating causes, namely from events which concern the soul and from celestial phenomena. | |
From: report of Aristotle (works [c.330 BCE], Frag 10) by Sextus Empiricus - Against the Physicists (two books) I.20 | |
A reaction: The cosmos suggests order, and possible creation. What do events of the soul suggest? It doesn't seem to be its non-physical nature, because Aristotle is more of a functionalist. Puzzling. (It says later that gods are like the soul). |