34 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) |
4901 | Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world [Perry] |
Full Idea: I think knowledge and truth are a matter of correspondence to facts, despite all the energy spent showing the naïveté of this view. The connections of our ideas in our heads correspond to relations in the outside world. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: Yes. Modern books offer the difficulties of defining 'correspondence', and finding an independent account of 'facts', as conclusive objections, but I say a brain is a truth machine, and it had better be useful. Indefinability doesn't nullify concepts. |
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) |
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) |
4885 | Identity is a very weak relation, which doesn't require interdefinability, or shared properties [Perry] |
Full Idea: The truth of "a=b" doesn't require much of 'a' and 'b' other than that there is a single thing to which they both refer. They needn't be interdefinable, or have supervenient properties. In this sense, identity is a very weak relation. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §1.2) | |
A reaction: Interesting. This is seeing the epistemological aspects of identity. Ontologically, identity must invoke Leibniz's Law, and is the ultimately powerful 'relation'. A given student, and the cause of a crop circle, may APPEAR to be quite different. |
4899 | Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology [Perry] |
Full Idea: Using possible worlds to model truth-conditions of statements has led to considerable clarity about the logic of modality. Attempts to use the system for epistemic purposes, however, have been plagued by problems. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: Presumably what lurks behind this is a distinction between what is logically or naturally possible, and what appears to be possible from the perspective of a conscious mind. Is there a possible world in which I can fly? |
4898 | Possible worlds are indices for a language, or concrete realities, or abstract possibilities [Perry] |
Full Idea: Possible worlds can be thought of as indices for models of the language in question, or as concrete realities (David Lewis), or as abstract ways the world might be (Robert Stalnaker), or in various other ways. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: I strongly favour the Stalnaker route here. Reducing great metaphysics to mere language I find abhorrent, and I suspect that Lewis was trapped by his commitment to strong empiricism. We must embrace abstractions into our ontology. |
4887 | We try to cause other things to occur by causing mental events to occur [Perry] |
Full Idea: We try to cause other things to occur by causing mental events to occur. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §2.4) | |
A reaction: A small and obvious, but important, point. Mental causation isn't just thoughts leading to physical happenings. Here Perry means that events can be designed to cause thoughts, such as a threatening letter. Not much room for epiphenomenalism here. |
4884 | Brain states must be in my head, and yet the pain seems to be in my hand [Perry] |
Full Idea: The brain state will involve certain parts of the brain, whereas my feeling of pain seems to be located in my hand insofar as it has a bodily location. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §1.2) | |
A reaction: This seems important to me. The brain is a ventriloquist. Perry implies that pain is quasi-disembodied, but it isn't, it is just experienced as IN the hand. Perhaps it is in the hand? Cutting the nerves loses contact with the pain. |
4888 | It seems plausible that many animals have experiences without knowing about them [Perry] |
Full Idea: It seems quite plausible to me that many animals have experiences without knowing about them. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §3.1) | |
A reaction: I agree, which makes us acknowledge levels of consciousness, which probably applies to human experience as well. The simplest idea is to distinguish between experiences which involve concepts, and those which don't. Animals sometimes appear surprised. |
4891 | If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism [Perry] |
Full Idea: Epiphenomenalism is usually considered to be a form of dualism, but if we define it as the doctrine that conscious events are effects but not causes, it appears to be consistent with physicalism. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §4.2) | |
A reaction: Interesting. The theory was invented to put mind outside physics, and make the closure of physics possible. However, being capable of causing things seems to be a necessary condition for physical objects. An effect in one domain is a cause in another. |
4900 | Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent [Perry] |
Full Idea: Advocates of the mind-body identity theory typically claimed that identity between particular mental states and brain states was contingent, until Kripke argued persuasively that identity is always necessary. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: Kripke wanted to argue against the identity theory, but what he seems to have done is reformulate it into a much more powerful version (involving necessary identity). |
4892 | If physicalists stick with identity (not supervenience), Martian pain will not be like ours [Perry] |
Full Idea: The physicalist should not retreat to causal supervenience but should stick with identity. This means we will have to accept that a Martian and I (when in pain) are not in the same phenomenal state. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §4.3) | |
A reaction: We naturally presume that frogs feel pain as we do, but many different phenomenal states could lead to the same behavioural end. Only an unpleasant feeling is required. A foul smell would do. Frogs could function with inverted qualia, too. |
4889 | Although we may classify ideas by content, we individuate them differently, as their content can change [Perry] |
Full Idea: Although we classify ideas by content for many purposes, we do not individuate them by content. The content of an idea can change. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §3.2) | |
A reaction: As the compiler of this database, I find this very appealing. The mind works exactly like a database. I have a 'file' (Perry's word) marked "London", the content of which undergoes continual change. I am a database management system. |
4896 | The intension of an expression is a function from possible worlds to an appropriate extension [Perry] |
Full Idea: In possible-worlds semantics, expressions have intensions, which are functions from possible worlds to appropriate extensions (names to individuals, n-place predicates to n-tuples, and sentences to truth values, built from parts). | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: Interesting. Perry distinguishes 'referential' (or 'subject matter') content, which is prior to the link to extensions - a link which creates 'reflexive' content. He is keen that they should not become confused. True knowledge is 'situated'. |
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. |
4897 | A proposition is a set of possible worlds for which its intension delivers truth [Perry] |
Full Idea: The proposition expressed by a sentence can be thought of as a set of possible worlds, the worlds for which its intension delivers truth. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1) | |
A reaction: It has always struck me as important to hang on to the concept of a 'proposition' (over and above sentences). This idea gives a metaphysics for the concept, and the 'language of thought' offers appropriate brain structures. A neat picture. |
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. |
4890 | A sharp analytic/synthetic line can rarely be drawn, but some concepts are central to thought [Perry] |
Full Idea: Although there is seldom a sharp analytic/synthetic distinction to be drawn in the case of our concepts, there are clearly things that are more and less central. | |
From: John Perry (Knowledge, Possibility and Consciousness [2001], §3.2) | |
A reaction: Most Americans seem enslaved to Quine on this one, so it is nice to see the obvious being stated for once. Human thought is an organic offshoot of the natural world. To think it is all arbitrary and changeable is human arrogance. |
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. |
20746 | One is not born, but rather becomes a woman [Beauvoir] |
Full Idea: One is not born, but rather becomes a woman. | |
From: Simone de Beauvoir (The Second Sex [1952], p.301 (or 267)), quoted by Kevin Aho - Existentialism: an introduction 2 'Phenomenology' | |
A reaction: This has become the principle idea in modern discussions of gender. It divides gender from sex, rather as Locke divided person from human being. It is an abstraction. It is part of the Hegelian-Marxist idea that persons are moulded by culture. |
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) |