25 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'. |
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 |
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 |
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) |
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) | |
A reaction: Is that 'first' in time, or in priority? If they are the grounds of being, how could there ever be non-necessary existents? Why would necessary being permit intruders? |
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. |
7260 | If there are intuited moral facts, why should we care about them? [Dancy,J] |
Full Idea: Critics asked (of intuitionism) why, if moral facts are as the intuitionists say, we should care about them at all. | |
From: Jonathan Dancy (Intuitionism [1991]) | |
A reaction: It is a good question, as we don't care much about other a priori truths, such as the square root of 169. |
7261 | Internalists say that moral intuitions are motivating; externalist say a desire is also needed [Dancy,J] |
Full Idea: There is an internalist view of intuitionism, saying that to accept that one's action is wrong is itself to be motivated not to do it. Externalists (like Ross) say that moral judgements need the help of an independent desire to motivate us. | |
From: Jonathan Dancy (Intuitionism [1991]) | |
A reaction: The internalists would be closer to Kant or Plato (for whom reason or pure ideas motivate), while externalist would favour Hume's belief/desire account of human actions. I like Kant and Plato, but Hume is more plausible. Dancy disagrees (Idea 7262). |
7262 | Obviously judging an action as wrong gives us a reason not to do it [Dancy,J] |
Full Idea: It is ludicrous to say that we might accept an action is outrageously wrong and still think of this as not in itself giving us good reason to hold back. | |
From: Jonathan Dancy (Intuitionism [1991]) | |
A reaction: If we think of some dreadful man-made famine in a remote continent, our judgement may well give a reason to act, but apathy usually intervenes. We are discussing a purely theoretical motive on the one hand, and an actual motivator on the other. |
7265 | Moral facts are not perceived facts, but perceived reasons for judgements [Dancy,J] |
Full Idea: I intend to suggest that moral facts are best thought of not as facts perceived but as reasons recognised in the exercise of practical moral judgement. | |
From: Jonathan Dancy (Intuitionism [1991]) | |
A reaction: I'm not convinced by this modified version. Why should the fact that someone is in pain be, in itself, a reason to prevent it? There are different cultural traditions for response to the pain of others. We are the squeamish tradition. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |
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) |