24 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) |
| 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 |
| 14263 | Strong Kleene disjunction just needs one true disjunct; Weak needs the other to have some value [Fine,K] |
| Full Idea: Under strong Kleene tables, a disjunction will be true if one of the disjuncts is true, regardless of whether or not the other disjunct has a truth-value; under the weak table it is required that the other disjunct also have a value. So for other cases. | |
| From: Kit Fine (Some Puzzles of Ground [2010], n7) | |
| A reaction: [see also p.111 of Fine's article] The Kleene tables seem to be the established form of modern three-valued logic, with the third value being indeterminate. |
| 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) |
| 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) |
| 14262 | Formal grounding needs transitivity of grounding, no self-grounding, and the existence of both parties [Fine,K] |
| Full Idea: The general formal principles of grounding are Transitivity (A«B, B«C/A«C: if A helps ground B and B helps C, then A helps C), Irreflexivity (A«A/absurd: A can't ground itself) and Factivity (A«B/A; A«/B: for grounding both A and B must be the case). | |
| From: Kit Fine (Some Puzzles of Ground [2010], 4) |
| 14365 | Scientific understanding is always the grasping of a correct explanation [Strevens] |
| Full Idea: I defend what I call the 'simple view', that scientific understanding is that state produced, and only produced, by grasping a correct explanation. | |
| From: Michael Strevens (No Understanding without Explanation [2011], Intro) | |
| A reaction: I like this because it clearly states what I take to be the view of Aristotle, and the key to understanding the whole of that philosopher's system. I take the view to be correct. |
| 14368 | We may 'understand that' the cat is on the mat, but not at all 'understand why' it is there [Strevens] |
| Full Idea: 'Understanding why' is quite separate from 'understanding that': you might be exquisitely, incandescently aware of the cat's being on the mat without having the slightest clue how it got there. My topic is understanding why. | |
| From: Michael Strevens (No Understanding without Explanation [2011], 2) | |
| A reaction: Can't we separate 'understand how' from 'understand why'? I may know that someone dropped a cat through my letterbox, but more understanding would still be required. (He later adds understanding 'with' a theory). |
| 14369 | Understanding is a precondition, comes in degrees, is active, and holistic - unlike explanation [Strevens] |
| Full Idea: Objectors to the idea that understanding requires explanation say that understanding is a precondition for explanation, that understanding comes in degrees, that understanding is active, and that it is holistic - all unlike explanations. | |
| From: Michael Strevens (No Understanding without Explanation [2011], 4) | |
| A reaction: He works through these four objections and replies to them, in defence of the thesis in Idea 14365. I agree with Strevens on this. |
| 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) |