30 ideas
| 1708 | In "Callias is just/not just/unjust", which of these are contraries? [Aristotle] |
| Full Idea: Take, for example, "Callias is just", "Callias is not just", and "Callias is unjust"; which of these are contraries? | |
| From: Aristotle (On Interpretation [c.330 BCE], 23a31) |
| 19463 | Induction assumes some uniformity in nature, or that in some respects the future is like the past [Ayer] |
| Full Idea: In all inductive reasoning we make the assumption that there is a measure of uniformity in nature; or, roughly speaking, that the future will, in the appropriate respects, resemble the past. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii) | |
| A reaction: I would say that nature is 'stable'. Nature changes, so a global assumption of total uniformity is daft. Do we need some global uniformity assumptions, if the induction involved is local? I would say yes. Are all inductions conditional on this? |
| 1703 | It is necessary that either a sea-fight occurs tomorrow or it doesn't, though neither option is in itself necessary [Aristotle] |
| Full Idea: It is not necessary for a sea-battle to take place tomorrow, nor for one not to take place tomorrow - though it is necessary for one to take place OR not take place tomorrow. | |
| From: Aristotle (On Interpretation [c.330 BCE], 19a30) |
| 1704 | Statements are true according to how things actually are [Aristotle] |
| Full Idea: Statements are true according to how things actually are. | |
| From: Aristotle (On Interpretation [c.330 BCE], 19a33) |
| 22272 | Aristotle's later logic had to treat 'Socrates' as 'everything that is Socrates' [Potter on Aristotle] |
| Full Idea: When Aristotle moved from basic name+verb (in 'De Interpretatione') to noun+noun logic...names had to be treated as special cases, so that 'Socrates' is treated as short for 'everything that is Socrates'. | |
| From: comment on Aristotle (On Interpretation [c.330 BCE]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 02 'Supp' | |
| A reaction: Just the sort of rewriting that Russell introduced for definite descriptions. 'Twas ever the logicians' fate to shoehorn ordinary speech into awkward containers. |
| 9405 | Square of Opposition: not both true, or not both false; one-way implication; opposite truth-values [Aristotle] |
| Full Idea: Square of Opposition: horizontals - 'contraries' can't both be true, and 'subcontraries' can't both be false; verticals - 'subalternatives' have downwards-only implication; diagonals - 'contradictories' have opposite truth values. | |
| From: Aristotle (On Interpretation [c.330 BCE], Ch.12-13) | |
| A reaction: This is still used in modern discussion (e.g. by Stalnaker against Kripke), and there is a modal version of it (Fitting and Mendelsohn p.7). Corners read: 'All F are G', 'No F are G', 'Some F are G' and 'Some F are not G'. |
| 9728 | Modal Square 1: □P and ¬◊¬P are 'contraries' of □¬P and ¬◊P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 1: 'It is necessary that P' and 'It is not possible that not P' are the contraries (not both true) of 'It is necessary that not P' and 'It is not possible that P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12a) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 9729 | Modal Square 2: ¬□¬P and ◊P are 'subcontraries' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 2: 'It is not necessary that not P' and 'It is possible that P' are the subcontraries (not both false) of 'It is not necessary that P' and 'It is possible that not P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12b) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 9730 | Modal Square 3: □P and ¬◊¬P are 'contradictories' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 3: 'It is necessary that P' and 'It is not possible that not P' are the contradictories (different truth values) of 'It is not necessary that P' and 'It is possible that not P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12c) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 9731 | Modal Square 4: □¬P and ¬◊P are 'contradictories' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 4: 'It is necessary that not P' and 'It is not possible that P' are the contradictories (different truth values) of 'It is not necessary that not P' and 'It is possible that P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12d) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 9732 | Modal Square 5: □P and ¬◊¬P are 'subalternatives' of ¬□¬P and ◊P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 5: 'It is necessary that P' and 'It is not possible that not P' are the subalternatives (first implies second) of 'It is not necessary that not P' and 'It is possible that P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12e) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 9733 | Modal Square 6: □¬P and ¬◊P are 'subalternatives' of ¬□P and ◊¬P [Aristotle, by Fitting/Mendelsohn] |
| Full Idea: Modal Square of Opposition 6: 'It is necessary that not P' and 'It is not possible that P' are the subalternatives (first implies second) of 'It is not necessary that P' and 'It is possible that not P'. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], Ch.12f) by M Fitting/R Mendelsohn - First-Order Modal Logic 1.4 |
| 21593 | In talking of future sea-fights, Aristotle rejects bivalence [Aristotle, by Williamson] |
| Full Idea: Unlike Aristotle, Stoics did not reject Bivalence for future contingencies; it is true or false that there will be a sea-fight tomorrow. | |
| From: report of Aristotle (On Interpretation [c.330 BCE], 19a31) by Timothy Williamson - Vagueness 1.2 | |
| A reaction: I'd never quite registered this simple account of the sea-fight. As Williamson emphasises, one should not lightly reject the principle of bivalence. Has Aristotle entered a slippery slope? Stoics disagreed with Aristotle. |
| 1701 | A prayer is a sentence which is neither true nor false [Aristotle] |
| Full Idea: A prayer is a sentence which is neither true nor false. | |
| From: Aristotle (On Interpretation [c.330 BCE], 17a01) |
| 18914 | Davidson controversially proposed to quantify over events [Davidson, by Engelbretsen] |
| Full Idea: An alternative, and still controversial, extension of first-order logic is due to Donald Davidson, who allows for quantification over events. | |
| From: report of Donald Davidson (The Individuation of Events [1969]) by George Engelbretsen - Trees, Terms and Truth 3 | |
| A reaction: I'm suddenly thinking this is quite an attractive proposal. We need to quantify over facts, or states of affairs, or events, or some such thing, to talk about the world properly. Objects, predicates and sets/parts is too sparse. I like facts. |
| 1706 | Non-existent things aren't made to exist by thought, because their non-existence is part of the thought [Aristotle] |
| Full Idea: It is not true to say that what is not, since it is thought about, is something that is; for what is thought about it is not that it is, but that it is not. | |
| From: Aristotle (On Interpretation [c.330 BCE], 21a31) | |
| A reaction: At least there has been one philosopher who was quite clear about the distinction between a thought and what the thought is about (its content). Often forgotten! |
| 1707 | Maybe necessity and non-necessity are the first principles of ontology [Aristotle] |
| Full Idea: Perhaps the necessary and non-necessary are first principles of everything's either being or not being. | |
| From: Aristotle (On Interpretation [c.330 BCE], 23a18) |
| 9843 | You can't identify events by causes and effects, as the event needs to be known first [Dummett on Davidson] |
| Full Idea: Davidson's criterion for the identity of events is a mistake, because we cannot know the causes and effects of an event until we know what that event comprises. | |
| From: comment on Donald Davidson (The Individuation of Events [1969]) by Michael Dummett - Frege philosophy of mathematics Ch.10 | |
| A reaction: How many attempts by analytical philosophers to give necessary and sufficient conditions for things seem to founder in this way. Their predecessor is at the end of 'Theaetetus'; you have to know what the sun is before you can define it. |
| 14602 | Events can only be individuated causally [Davidson, by Schaffer,J] |
| Full Idea: Davidson claims that events can only be individuated causally. | |
| From: report of Donald Davidson (The Individuation of Events [1969], 3) by Jonathan Schaffer - Causation and Laws of Nature 3 | |
| A reaction: Schaffer rejects this in favour of individuating events by their spatiotemporal locations and intrinsic natures (which seem to be property instantiations, a la Kim). Schaffer was a pupil of David Lewis. |
| 14004 | We need events for action statements, causal statements, explanation, mind-and-body, and adverbs [Davidson, by Bourne] |
| Full Idea: Davidson claims that we require the existence of events in order to make sense of a) action statements, b) causal statements, c) explanation, d) the mind-body problem, and e) the logic of adverbial modification. | |
| From: report of Donald Davidson (The Individuation of Events [1969], Intro IIb) by Craig Bourne - A Future for Presentism | |
| A reaction: Events are a nice shorthand, but I don't like them in a serious ontology. Prior says there objects and what happens to them; Kim reduces events to other things. Processes are more clearly individuated than events. |
| 8278 | The claim that events are individuated by their causal relations to other events is circular [Lowe on Davidson] |
| Full Idea: Davidson has urged that events are individuated by the causal relations which they bear to one another, in accordance with the principle that events are identical just in case they have the same causes and effects. But the principle is viciously circular. | |
| From: comment on Donald Davidson (The Individuation of Events [1969]) by E.J. Lowe - The Possibility of Metaphysics 7.4 | |
| A reaction: You wouldn't want to identify a person just by their relationships, even though those will certainly be unique. Generally it is what I am (right now) naming as the Functional Fallacy: believing that specifying the function of x explains x. |
| 19461 | Knowing I exist reveals nothing at all about my nature [Ayer] |
| Full Idea: To know that one exists is not to know anything about oneself any more than knowing that 'this' exists is knowing anything about 'this'. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: Descartes proceeds to define himself as a 'thinking thing', inferring that thinking is his essence. Ayer casts nice doubt on that. |
| 19459 | To say 'I am not thinking' must be false, but it might have been true, so it isn't self-contradictory [Ayer] |
| Full Idea: To say 'I am not thinking' is self-stultifying since if it is said intelligently it must be false: but it is not self-contradictory. The proof that it is not self-contradictory is that it might have been false. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: If it doesn't imply a contradiction, then it is not a necessary truth, which is what it is normally taken to be. Is 'This is a sentence' necessarily true? It might not have been one, if the rules of English syntax changed recently. |
| 19460 | 'I know I exist' has no counterevidence, so it may be meaningless [Ayer] |
| Full Idea: If there is no experience at all of finding out that one is not conscious, or that one does not exist, ..it is tempting to say that sentences like 'I exist', 'I am conscious', 'I know that I exist' do not express genuine propositions. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: This is, of course, an application of the somewhat discredited verification principle, but the fact that strictly speaking the principle has been sort of refuted does not mean that we should not take it seriously, and be influenced by it. |
| 19464 | We only discard a hypothesis after one failure if it appears likely to keep on failing [Ayer] |
| Full Idea: Why should a hypothesis which has failed the test be discarded unless this shows it to be unreliable; that is, having failed once it is likely to fail again? There is no contradiction in a hypothesis that was falsified being more likely to pass in future. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii) | |
| A reaction: People may become more likely to pass a test after they have failed at the first attempt. Birds which fail to fly at the first attempt usually achieve total mastery of it. There are different types of hypothesis here. |
| 19462 | Induction passes from particular facts to other particulars, or to general laws, non-deductively [Ayer] |
| Full Idea: Inductive reasoning covers all cases in which we pass from a particular statement of fact, or set of them, to a factual conclusion which they do not formally entail. The inference may be to a general law, or by analogy to another particular instance. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.viii) | |
| A reaction: My preferred definition is 'learning from experience' - which I take to be the most rational behaviour you could possibly imagine. I don't think a definition should be couched in terms of 'objects' or 'particulars'. |
| 2337 | For Aristotle meaning and reference are linked to concepts [Aristotle, by Putnam] |
| Full Idea: In 'De Interpretatione' Aristotle laid out an enduring theory of reference and meaning, in which we understand a word or any other sign by associating that word with a concept. This concept determines what the word refers to. | |
| From: report of Aristotle (On Interpretation [c.330 BCE]) by Hilary Putnam - Representation and Reality 2 p.19 | |
| A reaction: Sounds right to me, despite all this Wittgensteinian stuff about beetles in boxes. When you meet a new technical term in philosophy, you must struggle to fully grasp the concept it proposes. |
| 13763 | Spoken sounds vary between people, but are signs of affections of soul, which are the same for all [Aristotle] |
| Full Idea: Spoken sounds are symbols of affections in the soul, ...and just as written marks are not the same for all men, neither are spoken sounds. But what these are in the first place signs of - affections of the soul - are the same for all. | |
| From: Aristotle (On Interpretation [c.330 BCE], 16a03-08) | |
| A reaction: Loux identifies this passage as the source of the 'conceptualist' view of propositions, which I immediately identify with. The view that these propositions are 'the same for all' is plausible for normal objects, but dubious for complex abstractions. |
| 1705 | It doesn't have to be the case that in opposed views one is true and the other false [Aristotle] |
| Full Idea: It is not necessary that of every affirmation and opposite negation one should be true and the other false. For what holds for things that are does not hold for things that are not but may possibly be or not be. | |
| From: Aristotle (On Interpretation [c.330 BCE], 19a39) | |
| A reaction: Thus even if Bivalence holds, and the only truth-values are T and F, it doesn't follow that Excluded Middle holds, which says that every proposition must have one of those two values. |
| 1702 | Things may be necessary once they occur, but not be unconditionally necessary [Aristotle] |
| Full Idea: To say that everything that is, is of necessity, when it is, is not the same as saying unconditionally that it is of necessity. | |
| From: Aristotle (On Interpretation [c.330 BCE], 19a25) |