76 ideas
| 21959 | Metaphysics is the most general attempt to make sense of things [Moore,AW] |
| Full Idea: Metaphysics is the most general attempt to make sense of things. | |
| From: A.W. Moore (The Evolution of Modern Metaphysics [2012], Intro) | |
| A reaction: This is the first sentence of Moore's book, and a touchstone idea all the way through. It stands up well, because it says enough without committing to too much. I have to agree with it. It implies explanation as the key. I like generality too. |
| 6887 | Linguistic philosophy approaches problems by attending to actual linguistic usage [Mautner] |
| Full Idea: Linguistic philosophy gives careful attention to actual linguistic usage as a method of dealing with problems of philosophy, resulting in either their solution or dissolution. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.318) | |
| A reaction: This approach is now deeply discredited and unfashionable, and, I think (on the whole), rightly so. Philosophy should aim a little higher in (say) epistemology than merely describing how people use words like 'know' and 'believe' and 'justify'. |
| 6881 | Analytic philosophy studies the unimportant, and sharpens tools instead of using them [Mautner] |
| Full Idea: Critics of analytic philosophers accuse them of excessive attention to relatively unimportant matters, and of being more interested in sharpening tools than in using them. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.111) | |
| A reaction: The last part is a nice comment. Both criticisms seem to me to contain some justice, but recently things have improved (notably in the new attention paid by analytical philosophy to metaphysics). In morality analytic philosophy seems superior. |
| 5439 | The 'hermeneutic circle' says parts and wholes are interdependent, and so cannot be interpreted [Mautner] |
| Full Idea: The 'hermeneutic circle' consists in the fact that an interpretation of part of a text requires a prior understanding of the whole, and the interpretation of the whole requires a prior understanding of its parts. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.247) | |
| A reaction: This strikes me as a benign circle, solved the way Aristotle solves the good man/good action circle. You make a start somewhere, like a child learning to speak, and work your way into the circle. Not really a problem. |
| 9959 | 'Real' definitions give the essential properties of things under a concept [Mautner] |
| Full Idea: A 'real definition' (as opposed to a linguistic one) is a statement which gives the essential properties of the things to which a given concept applies. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], 'definition') | |
| A reaction: This is often seen as old-fashioned, Aristotelian, and impossible to achieve, but I like it and aspire to it. One can hardly be precise about which properties are 'essential' to something, but there are clear cases. Your 'gold' had better not be brass. |
| 9961 | 'Contextual definitions' replace whole statements, not just expressions [Mautner] |
| Full Idea: Usually in a definition the definiens (definition) can replace the definiendum (expression defined), but in a 'contextual definition' only the whole statement containing the definiens can replace the whole statement containing the definiendum. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], 'definition') | |
| A reaction: These definitions are crucial to Frege's enterprise in the 'Grundlagen'. Logicians always want to achieve definition with a single neat operation, but in ordinary language we talk around a definition, giving a variety of possibilities (as in teaching). |
| 9958 | Recursive definition defines each instance from a previous instance [Mautner] |
| Full Idea: An example of a recursive definition is 'y is an ancestor of x' is defined as 'y is a parent of x, or y is a parent of an ancestor of x'. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], 'definition') | |
| A reaction: From this example I guess that 'ancestor' means 'friend'. Or have I misunderstood? I think we need to define 'grand-parent' as well, and then offer the definition of 'ancestor' with the words 'and so on...'. Essentially, it is mathematical induction. |
| 9960 | A stipulative definition lays down that an expression is to have a certain meaning [Mautner] |
| Full Idea: A stipulative definition lays down that a given linguistic expression is to have a certain meaning; this is why they cannot be said to be correct or incorrect. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], 'definition') | |
| A reaction: These are uncontroversial when they are explicitly made in writing by a single person. The tricky case is where they are implicitly made in conversation by a community. After a century or two these look like facts, their origin having been lost. |
| 9957 | Ostensive definitions point to an object which an expression denotes [Mautner] |
| Full Idea: Ostensive definitions explain what an expression means by pointing to an object, action, event, etc. denoted by the expression. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], 'definition') | |
| A reaction: These will need some context. If I define 'red' simply by pointing to a red square, you might conclude that 'red' means square. If I point to five varied red objects, you have to do the work of spotting the common ingredient. I can't mention 'colour'. |
| 6219 | The fallacy of composition is the assumption that what is true of the parts is true of the whole [Mautner] |
| Full Idea: The fallacy of composition is an inference relying on the invalid principle that whatever is true of every part is also true of the whole; thus, we cannot assume that because the members of a committee are rational, that the committee as a whole is. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.102) | |
| A reaction: This is a very common and very significant fallacy, which is perpetrated by major philosophers like Aristotle (Idea 31), unlike most of the other informal fallacies. |
| 9738 | Each line of a truth table is a model [Fitting/Mendelsohn] |
| Full Idea: Each line of a truth table is, in effect, a model. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) | |
| A reaction: I find this comment illuminating. It is being connected with the more complex models of modal logic. Each line of a truth table is a picture of how the world might be. |
| 9727 | Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn] |
| Full Idea: For modal logic we add to the syntax of classical logic two new unary operators □ (necessarily) and ◊ (possibly). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.3) |
| 9726 | We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn] |
| Full Idea: We let 'R' be the accessibility relation: xRy is read 'y is accessible from x'. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.5) |
| 9737 | The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn] |
| Full Idea: The symbol ||- is used for the 'forcing' relation, as in 'Γ ||- P', which means that P is true in world Γ. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 13136 | The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn] |
| Full Idea: A 'prefix' is a finite sequence of positive integers. A 'prefixed formula' is an expression of the form σ X, where σ is a prefix and X is a formula. A prefix names a possible world, and σ.n names a world accessible from that one. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13727 | A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn] |
| Full Idea: In 'constant domain' semantics, the domain of each possible world is the same as every other; in 'varying domain' semantics, the domains need not coincide, or even overlap. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.5) |
| 9734 | Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn] |
| Full Idea: Modern modal logic takes into consideration the way the modal relates the possible worlds, called the 'accessibility' relation. .. We let R be the accessibility relation, and xRy reads as 'y is accessible from x. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.5) | |
| A reaction: There are various types of accessibility, and these define the various modal logics. |
| 9736 | A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn] |
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Full Idea:
A 'model' is a frame plus a specification of which propositional letters are true at which worlds. It is written as |
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| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9735 | A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn] |
|
Full Idea:
A 'frame' consists of a non-empty set G, whose members are generally called possible worlds, and a binary relation R, on G, generally called the accessibility relation. We say the frame is the pair |
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| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9741 | Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn] |
| Full Idea: A relation R is 'reflexive' if every world is accessible from itself; 'transitive' if the first world is related to the third world (ΓRΔ and ΔRΩ → ΓRΩ); and 'symmetric' if the accessibility relation is mutual. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.7) | |
| A reaction: The different systems of modal logic largely depend on how these accessibility relations are specified. There is also the 'serial' relation, which just says that any world has another world accessible to it. |
| 9740 | If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn] |
| Full Idea: If a proposition is possibly true in a world, then it is also true in some world which is accessible from that world. That is: Γ ||- ◊X ↔ for some Δ ∈ G, ΓRΔ then Δ ||- X. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 9739 | If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn] |
| Full Idea: If a proposition is necessarily true in a world, then it is also true in all worlds which are accessible from that world. That is: Γ ||- □X ↔ for every Δ ∈ G, if ΓRΔ then Δ ||- X. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.6) |
| 13137 | Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for conjunctions: a) if σ X ∧ Y then σ X and σ Y b) if σ ¬(X ∧ Y) then σ ¬X or σ ¬Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13140 | Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for biconditionals: a) if σ (X ↔ Y) then σ (X → Y) and σ (Y → X) b) if σ ¬(X ↔ Y) then σ ¬(X → Y) or σ ¬(Y → X) | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13139 | Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for implications: a) if σ ¬(X → Y) then σ X and σ ¬Y b) if σ X → Y then σ ¬X or σ Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13143 | Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for universal modality: a) if σ ¬◊ X then σ.m ¬X b) if σ □ X then σ.m X , where m refers to a world that can be seen (rather than introducing a new world). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) | |
| A reaction: Note that the universal rule of □, usually read as 'necessary', only refers to worlds which can already be seen, whereas possibility (◊) asserts some thing about a new as yet unseen world. |
| 13149 | S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn] |
| Full Idea: Simplified S5 rules: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X. 'n' picks any world; in a) and b) 'k' asserts a new world; in c) and d) 'k' refers to a known world | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13141 | Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn] |
| Full Idea: General tableau rule for negation: if σ ¬¬X then σ X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13138 | Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for disjunctions: a) if σ ¬(X ∨ Y) then σ ¬X and σ ¬Y b) if σ X ∨ Y then σ X or σ Y | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) |
| 13142 | Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn] |
| Full Idea: General tableau rules for existential modality: a) if σ ◊ X then σ.n X b) if σ ¬□ X then σ.n ¬X , where n introduces some new world (rather than referring to a world that can be seen). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.2) | |
| A reaction: Note that the existential rule of ◊, usually read as 'possibly', asserts something about a new as yet unseen world, whereas □ only refers to worlds which can already be seen, |
| 13144 | T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn] |
| Full Idea: System T reflexive rules (also for B, S4, S5): a) if σ □X then σ X b) if σ ¬◊X then σ ¬X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13145 | D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn] |
| Full Idea: System D serial rules (also for T, B, S4, S5): a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13146 | B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System B symmetric rules (also for S5): a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13147 | 4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System 4 transitive rules (also for K4, S4, S5): a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 13148 | 4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn] |
| Full Idea: System 4r reversed-transitive rules (also for S5): a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [where n is a world which already occurs] | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 2.3) |
| 9742 | The system K has no accessibility conditions [Fitting/Mendelsohn] |
| Full Idea: The system K has no frame conditions imposed on its accessibility relation. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) | |
| A reaction: The system is named K in honour of Saul Kripke. |
| 13114 | □P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn] |
| Full Idea: System D is usually thought of as Deontic Logic, concerning obligations and permissions. □P → P is not valid in D, since just because an action is obligatory, it does not follow that it is performed. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.12.2 Ex) |
| 9743 | The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system D has the 'serial' condition imposed on its accessibility relation - that is, every world must have some world which is accessible to it. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9744 | The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system T has the 'reflexive' condition imposed on its accessibility relation - that is, every world must be accessible to itself. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9746 | The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system K4 has the 'transitive' condition imposed on its accessibility relation - that is, if a relation holds between worlds 1 and 2 and worlds 2 and 3, it must hold between worlds 1 and 3. The relation carries over. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9745 | The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system B has the 'reflexive' and 'symmetric' conditions imposed on its accessibility relation - that is, every world must be accessible to itself, and any relation between worlds must be mutual. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system S4 has the 'reflexive' and 'transitive' conditions imposed on its accessibility relation - that is, every world is accessible to itself, and accessibility carries over a series of worlds. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) |
| 9748 | System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
| Full Idea: The system S5 has the 'reflexive', 'symmetric' and 'transitive' conditions imposed on its accessibility relation - that is, every world is self-accessible, and accessibility is mutual, and it carries over a series of worlds. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.8) | |
| A reaction: S5 has total accessibility, and hence is the most powerful system (though it might be too powerful). |
| 9404 | Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn] |
| Full Idea: P→◊P is usually considered to be valid, but its converse, ◊P→P is not, so (by Frege's own criterion) P and possibly-P differ in conceptual content, and there is no reason why logic should not be widened to accommodate this. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.2) | |
| A reaction: Frege had denied that modality affected the content of a proposition (1879:p.4). The observation here is the foundation for the need for a modal logic. |
| 13112 | In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn] |
| Full Idea: In epistemic logic the knower is treated as logically omniscient. This is puzzling because one then cannot know something and yet fail to know that one knows it (the Principle of Positive Introspection). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.11) | |
| A reaction: This is nowadays known as the K-K Problem - to know, must you know that you know. Broadly, we find that externalists say you don't need to know that you know (so animals know things), but internalists say you do need to know that you know. |
| 13111 | Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn] |
| Full Idea: In epistemic logic we read Υ as 'KaP: a knows that P', and ◊ as 'PaP: it is possible, for all a knows, that P' (a is an individual). For belief we read them as 'BaP: a believes that P' and 'CaP: compatible with everything a believes that P'. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.11) | |
| A reaction: [scripted capitals and subscripts are involved] Hintikka 1962 is the source of this. Fitting and Mendelsohn prefer □ to read 'a is entitled to know P', rather than 'a knows that P'. |
| 13113 | F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn] |
| Full Idea: We introduce four future and past tense operators: FP: it will sometime be the case that P. PP: it was sometime the case that P. GP: it will always be the case that P. HP: it has always been the case that P. (P itself is untensed). | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 1.10) | |
| A reaction: Temporal logic begins with A.N. Prior, and starts with □ as 'always', and ◊ as 'sometimes', but then adds these past and future divisions. Two different logics emerge, taking □ and ◊ as either past or as future. |
| 13728 | The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn] |
| Full Idea: The Converse Barcan says nothing passes out of existence in alternative situations. The Barcan says that nothing comes into existence. The two together say the same things exist no matter what the situation. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.9) | |
| A reaction: I take the big problem to be that these reflect what it is you want to say, and that does not keep stable across a conversation, so ordinary rational discussion sometimes asserts these formulas, and 30 seconds later denies them. |
| 13729 | The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn] |
| Full Idea: The Barcan formula corresponds to anti-monotonicity, and the Converse Barcan formula corresponds to monotonicity. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 6.3) |
| 6888 | Fuzzy logic is based on the notion that there can be membership of a set to some degree [Mautner] |
| Full Idea: Fuzzy logic is based upon fuzzy set-theory, in which the simple notion of membership of a set is replaced by a notion of membership to some degree. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.214) | |
| A reaction: The idea that something could be to some degree a 'heap of sand' sounds plausible, but Williamson and Sorensen claim that the vagueness is all in us (i.e. it is epistemological), and not in the world. This will scupper fuzzy logic. |
| 6877 | Entailment is logical requirement; it may be not(p and not-q), but that has problems [Mautner] |
| Full Idea: Entailment is the modern word saying that p logically follows from q. Its simplest definition is that you cannot have both p and not-q, but this has the problem that if p is impossible it will entail every possible proposition, which seems unacceptable. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.169) | |
| A reaction: The word 'entail' was introduced by G.E. Moore in 1920, in preference to 'imply'. It seems clear that we need terms for (say) active implication (q must be true if p is true) and passive implication (p must be false if q is false). |
| 6880 | Strict implication says false propositions imply everything, and everything implies true propositions [Mautner] |
| Full Idea: Strict implication [not(p and not-q)] carries the paradoxes that a false proposition (p) implies any proposition (q), and a true proposition (q) is materially implied by any proposition (p). | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.270) | |
| A reaction: This seems to show that we have two drastically different notions of implication; one (the logician's) is boring and is defined by a truth table; the other (the ordinary interesting one) says if you have one truth you can deduce a second. |
| 6879 | 'Material implication' is defined as 'not(p and not-q)', but seems to imply a connection between p and q [Mautner] |
| Full Idea: 'Material implication' is a term introduced by Russell which is defined as 'the conjunction of p and not-q is false', but carries a strong implication that p implies q, and so there must be some kind of connection between them, which is misleading. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.270) | |
| A reaction: Mautner says statements of the form 'if p then q' are better called 'conditionals' than 'material implications'. Clearly there is a need for more precise terminology here, as the underlying concepts seem simple enough. |
| 6878 | A person who 'infers' draws the conclusion, but a person who 'implies' leaves it to the audience [Mautner] |
| Full Idea: 'Implying' is different from 'inferring', because a person who infers draws the conclusion, but a person who implies leaves it to the audience to draw the conclusion. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.279) | |
| A reaction: I had always taken it just that the speaker does the implying and the audience does the inferring. Of course a speaker may not know what he or she is implying, but an audience must be aware of what it is inferring. |
| 6889 | Vagueness seems to be inconsistent with the view that every proposition is true or false [Mautner] |
| Full Idea: Vagueness is of great philosophical interest because it seems to be inconsistent with the view that every proposition is true or false. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.585) | |
| A reaction: This would explain why Williamson and Sorensen are keen to argue that vagueness is an epistemological (rather than ontological) problem. In ordinary English we are happy to say that p is 'sort of true' or 'fairly true'. |
| 9725 | 'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn] |
| Full Idea: 'Predicate abstraction' is a key idea. It is a syntactic mechanism for abstracting a predicate from a formula, providing a scoping mechanism for constants and function symbols similar to that provided for variables by quantifiers. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], Pref) |
| 6890 | Quantifiers turn an open sentence into one to which a truth-value can be assigned [Mautner] |
| Full Idea: In formal logic, quantifiers are operators that turn an open sentence into a sentence to which a truth-value can be assigned. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.464) | |
| A reaction: The standard quantifiers are 'all' and 'at least one'. The controversy is whether quantifiers actually assert existence, or whether (as McGinn says) they merely specify the subject matter of the sentence. I prefer the latter. |
| 13730 | The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn] |
| Full Idea: Equality has caused much grief for modal logic. Many of the problems, which have struck at the heart of the coherence of modal logic, stem from the apparent violations of the Indiscernibility of Identicals. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 7.1) | |
| A reaction: Thus when I say 'I might have been three inches taller', presumably I am referring to someone who is 'identical' to me, but who lacks one of my properties. A simple solution is to say that the person is 'essentially' identical. |
| 6882 | Counterfactuals presuppose a belief (or a fact) that the condition is false [Mautner] |
| Full Idea: A conditional is called counterfactual because its use seems to presuppose that the user believes its antecedent to be false. Some insist that the antecedent must actually be false. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.114) | |
| A reaction: I am inclined to favour the stricter second version. "If I am on Earth then I have weight" hardly sounds counterfactual. However, in "If there is a God then I will be saved" it is not clear whether it is counterfactual, so it had better be included. |
| 6886 | Counterfactuals are not true, they are merely valid [Mautner] |
| Full Idea: One view of counterfactuals says they are not true, but are merely valid. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.114) | |
| A reaction: This makes counterfactuals a branch of logic rather than of metaphysics. I find the metaphysical view more exciting as they are part of speculation and are beyond the capacity of computers (which I suspect they are). |
| 6885 | Counterfactuals are true if in every world close to actual where p is the case, q is also the case [Mautner] |
| Full Idea: Another view of counterfactuals (Lewis, Pollock, Stalnaker) is that they are true if at every possible world at which it is the case that p, and which is otherwise as similar as possible to the actual world, it is also the case that q. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.114) | |
| A reaction: This seems a good way if putting if, like Lewis, you actually believe in the reality of possible worlds, because then you are saying a counterfactual is made true by a set of facts. Otherwise it is not clear what the truth-maker is here. |
| 6884 | Counterfactuals say 'If it had been, or were, p, then it would be q' [Mautner] |
| Full Idea: A counterfactual conditional (or 'counterfactual') is a proposition or sentence of the form 'If it had been the case that p, then it would have been the case that q', or 'If it were the case that p, then it would be the case that q'. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.114) | |
| A reaction: The first statement refers to the past, but the second (a subjunctive) refers to any situation at any time. We know more about inferences that we could have made in the past than we do about what is inferable at absolutely any time. |
| 6883 | Maybe counterfactuals are only true if they contain valid inference from premisses [Mautner] |
| Full Idea: One view of counterfactuals (Chisholm, Goodman, Rescher) is that they are only true if there is a valid logical inference from p and some other propositions of certain kinds (controversial) to q. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.115) | |
| A reaction: The aspiration that counterfactual claims should reduce to pure logic sounds a bit hopeful to me. Logic is precise, but assertions about how things would be is speculative and imaginative. |
| 5449 | Essentialism is often identified with belief in 'de re' necessary truths [Mautner] |
| Full Idea: Many writers identify essentialism with the belief in 'de re' necessary truths | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.179) | |
| A reaction: I like essentialism, but I cautious about this. If I accept that I have an essential personal identity as I write this, but that it could change over time, the same principle might apply to other natural essences. |
| 13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
| Full Idea: If □ is to be sensitive to the quality of the truth of a proposition in its scope, then it must be sensitive as to whether an object is picked out by an essential property or by a contingent one. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.3) | |
| A reaction: This incredibly simple idea strikes me as being powerful and important. ...However, creating illustrative examples leaves me in a state of confusion. You try it. They cite '9' and 'number of planets'. But is it just nominal essence? '9' must be 9. |
| 13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
| Full Idea: The property of 'possibly being a Republican' is as much a property of Bill Clinton as is 'being a democrat'. So we don't peel off his properties from world to world. Hence the bundle theory fits our treatment of objects better than bare particulars. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 7.3) | |
| A reaction: This bundle theory is better described in recent parlance as the 'modal profile'. I am reluctant to talk of a modal truth about something as one of its 'properties'. An objects, then, is a bundle of truths? |
| 13726 | Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn] |
| Full Idea: The main technical problem with counterpart theory is that the being-a-counterpart relation is, in general, neither symmetric nor transitive, so no natural logic of equality is forthcoming. | |
| From: M Fitting/R Mendelsohn (First-Order Modal Logic [1998], 4.5) | |
| A reaction: That is, nothing is equal to a counterpart, either directly or indirectly. |
| 6898 | Fallibilism is the view that all knowledge-claims are provisional [Mautner] |
| Full Idea: Fallibilism is the view, proposed by Peirce, and found in Reichenbach, Popper, Quine etc that all knowledge-claims are provisional and in principle revisable, or that the possibility of error is ever-present. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.194) | |
| A reaction: I think of this as footnote to all thought which reads "Note 1: but you never quite know". Personally I would call myself a fallibilist, and am surprise at anyone who doesn't. The point is that this does not negate 'knowledge'. I am fairly sure 2+3=5. |
| 21958 | Appearances are nothing beyond representations, which is transcendental ideality [Moore,AW] |
| Full Idea: Appearances in general are nothing outside our representations, which is just what we mean by transcendental ideality. | |
| From: A.W. Moore (The Evolution of Modern Metaphysics [2012], B535/A507) |
| 6452 | 'Sense-data' arrived in 1910, but it denotes ideas in Locke, Berkeley and Hume [Mautner] |
| Full Idea: The term 'sense-data' gained currency around 1910, through writings of Moore and Russell, but it seems to denote at least some of the things referred to as 'ideas of sense' (Locke), or 'ideas' and 'sensible qualities' (Berkeley), or 'impressions' (Hume). | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.518) | |
| A reaction: See also Hobbes in Idea 2356 for an even earlier version. It looks as if the concept of sense-data is almost unavoidable for empiricists, and yet most modern empiricists have rejected them. You still have to give an account of perceptual illusions. |
| 4783 | Observing lots of green x can confirm 'all x are green' or 'all x are grue', where 'grue' is arbitrary [Mautner, by PG] |
| Full Idea: Observing green emeralds can confirm 'all emeralds are green' or 'all emeralds are grue', where 'grue' is an arbitrary predicate meaning 'green until t and then blue'. Thus predictions are arbitrary, depending on how the property is described. | |
| From: report of Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.225) by PG - Db (ideas) | |
| A reaction: This increasingly strikes me as the sort of sceptical nonsense that is concocted by philosophers who are enthralled to language instead of reality. It does draw attention to an expectation of stability in induction, both in language and in nature. |
| 4782 | 'All x are y' is equivalent to 'all non-y are non-x', so observing paper is white confirms 'ravens are black' [Mautner, by PG] |
| Full Idea: If observing a white sheet of paper confirms that 'all non-black things are non-ravens', and that is logically equivalent to 'all ravens are black' (which it is), then the latter proposition is confirmed by irrelevant observations. | |
| From: report of Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.105) by PG - Db (ideas) | |
| A reaction: This seems to me more significant than the 'grue' paradox. If some observations can be totally irrelevant (except to God?), then some observations are much more relevant than others, so relevance is a crucial aspect of induction. |
| 6899 | The references of indexicals ('there', 'now', 'I') depend on the circumstances of utterance [Mautner] |
| Full Idea: Indexicals are expressions whose references depend on the circumstances of utterance, such as 'here', 'now', 'last month' 'I', 'you'. It was introduced by Peirce; Reichenbach called them 'token-reflexive', Russell 'ego-centric particulars'. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.272) | |
| A reaction: Peirce's terminology seems best. They obviously create great problems for any theory of reference which is rather theoretical and linguistic, such as by the use of descriptions. You can't understand 'Look at that!' without practical awareness. |
| 6896 | Double effect is the distinction between what is foreseen and what is intended [Mautner] |
| Full Idea: The doctrine of double effect is that there is a moral distinction between what is foreseen by an agent as a likely result of an action, and what is intended. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.150) | |
| A reaction: Abortion for a pregnancy threatening the mother's life. What always intrigues me is the effects which you didn't foresee because you couldn't be bothered to think about them. How much obligation do you have to try to foresee events? |
| 6897 | Double effect acts need goodness, unintended evil, good not caused by evil, and outweighing [Mautner] |
| Full Idea: It is suggested the double effect act requires 1) the act is good, 2) the bad effect is not intended, and is avoided if possible, 3) the bad effect doesn't cause the good result, 4) the good must outweigh the bad side effect. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.151) | |
| A reaction: It is suggested that these won't work for permissibility of an action, but they might be appropriate for blameworthiness. Personally I am rather impressed by the four-part framework here, whatever nitpicking objections others may have found. |
| 5452 | 'Essentialism' is opposed to existentialism, and claims there is a human nature [Mautner] |
| Full Idea: In philosophical anthropology, the view that there is a human nature or essence is called 'essentialism'. It became current in 1946 as a contrast to Sartre's existentialist view. | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.179) | |
| A reaction: Being a fan of Aristotle, I incline towards the older view, but you cannot get away from the fact that the human brain has similarities to a Universal Turing Machine, and diverse cultures produce very different individuals. |