40 ideas
| 14519 | It is a great good to show reverence for a wise man [Epicurus] |
| Full Idea: To show reverence for a wise man is itself a great good for him who reveres [the wise man]. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 32) | |
| A reaction: It is characteristic of Epicurus to move up a level in his thinking, and not merely respect wisdom, but ask after the value of his own respect. Compare Idea 14517. Nice. |
| 14518 | In the study of philosophy, pleasure and knowledge arrive simultaneously [Epicurus] |
| Full Idea: In philosophy the pleasure accompanies the knowledge. For the enjoyment does not come after the learning but the learning and the enjoyment are simultaneous. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 27) |
| 6420 | Only by analysing is progress possible in philosophy [Russell] |
| Full Idea: I remain firmly persuaded, in spite of some modern tendencies to the contrary, that only by analysing is progress possible, …for example, by analysing physics and perception, the problem of mind and matter can be completely solved. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.1) | |
| A reaction: I don't share his confidence in the second part of this, but I subscribe to the maxim that 'analsis is the path to wisdom'. It is a very western view, and lots of people (mostly of a mystical disposition) hate it, but I see no better path. |
| 6432 | Analysis gives new knowledge, without destroying what we already have [Russell] |
| Full Idea: It seems to me evident that, as in the case of impure water, analysis gives new knowledge without destroying any of the previously existing knowledge. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.11) | |
| A reaction: I agree. On the whole, opponents of analysis are sentimental mystics who are reluctant to think carefully about life. I'm not sure what careful and concentrated thought is capable of, apart from analysis. |
| 6437 | The theory of types makes 'Socrates and killing are two' illegitimate [Russell] |
| Full Idea: 'Socrates and killing are two' would be an illegitimate sentence according to the doctrine of types. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.14) | |
| A reaction: This nicely shows how Ryle's notion of a 'category mistake', although it is a commonsense observation of bogus reasoning, arises out of Russell's logical analysis of sets. Of course, the theory of types has its critics. |
| 6442 | Truth belongs to beliefs, not to propositions and sentences [Russell] |
| Full Idea: Truth and falsehood both belong primarily to beliefs, and only derivatively to propositions and sentences. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.15) | |
| A reaction: I'm not sure why a proposition which is date/place stamped ('it is raining, here and now') could not be considered a truth, even if no one believed it. Is not the proposition 'squares have four sides' true? |
| 14626 | In S5 matters of possibility and necessity are non-contingent [Williamson] |
| Full Idea: In system S5 matters of possibility and necessity are always non-contingent. | |
| From: Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 3) | |
| A reaction: This will be because if something is possible in one world (because it can be seen to be true in some possible world) it will be possible for all worlds (since they can all see that world in S5). |
| 6436 | I gradually replaced classes with properties, and they ended as a symbolic convenience [Russell] |
| Full Idea: My original use of classes was gradually more and more replaced by properties, and in the end disappeared except as a symbolic convenience. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.14) | |
| A reaction: I wish I knew what properties are. On the whole, though, I agree with this, because it is more naturalistic. We may place things in classes because of their properties, and this means there are natural classes, but classes can't have a life of their own. |
| 7528 | Leibniz bases everything on subject/predicate and substance/property propositions [Russell] |
| Full Idea: The metaphysics of Leibniz was explicitly based upon the doctrine that every proposition attributes a predicate to a subject and (what seemed to him almost the same thing) that every fact consists of a substance having a property. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.5) | |
| A reaction: I think it is realised now that although predicates tend to attribute properties to things, they are far from being the same thing. See Idea 4587, for example. Russell gives us an interesting foot in the door of Leibniz's complex system. |
| 6439 | Names are meaningless unless there is an object which they designate [Russell] |
| Full Idea: Unlike descriptions, names are meaningless unless there is an object which they designate. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.14) | |
| A reaction: This interests Russell because of its ontological implications. If we reduce language to names, we can have a pure ontology of 'objects'. We need a system for saying whether a description names something - which is his theory of definite descriptions. |
| 6423 | We tried to define all of pure maths using logical premisses and concepts [Russell] |
| Full Idea: The primary aim of our 'Principia Mathematica' was to show that all pure mathematics follows from purely logical premisses and uses only concepts definable in logical terms. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.7) | |
| A reaction: This spells out the main programme of logicism, by its great hero, Russell. The big question now is whether Gödel's Incompleteness Theorems have succeeded in disproving logicism. |
| 6424 | Formalists say maths is merely conventional marks on paper, like the arbitrary rules of chess [Russell] |
| Full Idea: The Formalists, led by Hilbert, maintain that arithmetic symbols are merely marks on paper, devoid of meaning, and that arithmetic consists of certain arbitrary rules, like the rules of chess, by which these marks can be manipulated. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.10) | |
| A reaction: I just don't believe that maths is arbitrary, and this view pushes me into the arms of the empiricists, who say maths is far more likely to arise from experience than from arbitrary convention. The key to maths is patterns. |
| 6425 | Formalism can't apply numbers to reality, so it is an evasion [Russell] |
| Full Idea: Formalism is perfectly adequate for doing sums, but not for the application of number, such as the simple statement 'there are three men in this room', so it must be regarded as an unsatisfactory evasion. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.10) | |
| A reaction: This seems to me a powerful and simple objection. The foundation of arithmetic is that there are three men in the room, not that one plus two is three. Three men and three ties make a pattern, which we call 'three'. |
| 6426 | Intuitionism says propositions are only true or false if there is a method of showing it [Russell] |
| Full Idea: The nerve of the Intuitionist theory, led by Brouwer, is the denial of the law of excluded middle; it holds that a proposition can only be accounted true or false when there is some method of ascertaining which of these it is. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.2) | |
| A reaction: He cites 'there are three successive sevens in the expansion of pi' as a case in point. This seems to me an example of the verificationism and anti-realism which is typical of that period. It strikes me as nonsense, but Russell takes it seriously. |
| 6419 | In 1899-1900 I adopted the philosophy of logical atomism [Russell] |
| Full Idea: In the years 1899-1900 I adopted the philosophy of logical atomism. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.1) | |
| A reaction: This is interesting (about Russell) because he only labelled it as 'logical atomism' in about 1912, and only wrote about it as such in 1918. It is helpful to understand that the theory of definite descriptions was part of his logical atomism. |
| 6438 | Complex things can be known, but not simple things [Russell] |
| Full Idea: I have come to think that, although many things can be known to be complex, nothing can be known to be simple. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.14) | |
| A reaction: This appears to be a rejection of his logical atomism. It goes with a general rebellion against foundationalist epistemology, because the empiricists foundations (e.g. Hume's impressions) seem devoid of all content. |
| 6434 | Facts are everything, except simples; they are either relations or qualities [Russell] |
| Full Idea: Facts, as I am using the word, consist always of relations between parts of a whole or qualities of single things; facts, in a word, are whatever there is except what (if anything) is completely simple. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.13) | |
| A reaction: This is the view that goes with Russell's 'logical atomism', where the 'completely simple' is used to build up the 'facts'. If World War One was a fact, was it a 'relation' or a 'quality'. Must events then be defined in terms of those two? |
| 6440 | Universals can't just be words, because words themselves are universals [Russell] |
| Full Idea: Those who dislike universals have thought that they could be merely words; the trouble with this view is that a word itself is a universal. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.14) | |
| A reaction: Russell gradually lost his faith in most things, but never in universals. I find it unconvincing that we might dismiss nominalism so easily. I'm not sure why the application of the word 'cat' could not just be conventional. |
| 14524 | Bodies are combinations of shape, size, resistance and weight [Epicurus] |
| Full Idea: Epicurus said that body was conceived as an aggregate of shape and size and resistance and weight. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE]) | |
| A reaction: [Source Sextus 'Adversus Mathematicos' 10.257] Note that this is how we 'conceive' them. They might be intrinsically different, except that Epicurus is pretty much a phenomenalist. |
| 14625 | Necessity is counterfactually implied by its negation; possibility does not counterfactually imply its negation [Williamson] |
| Full Idea: Modal thinking is logically equivalent to a type of counterfactual thinking. ...The necessary is that which is counterfactually implied by its own negation; the possible is that which does not counterfactually imply its own negation. | |
| From: Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 1) | |
| A reaction: I really like this, because it builds modality on ordinary imaginative thinking. He says you just need to grasp counterfactuals, and also negation and absurdity, and you can then understand necessity and possibility. We can all do that. |
| 14623 | Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B) [Williamson] |
| Full Idea: The strict conditional implies the counterfactual conditional: □(A⊃B) ⊃ (A□→B) - suppose that A would not have held without B holding too; then if A had held, B would also have held. | |
| From: Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 1) | |
| A reaction: [He then adds a reading of his formula in terms of possible worlds] This sounds rather close to modus ponens. If A implies B, and A is actually the case, what have you got? B! |
| 14624 | Counterfactual conditionals transmit possibility: (A□→B)⊃(◊A⊃◊B) [Williamson] |
| Full Idea: The counterfactual conditional transmits possibility: (A□→B) ⊃ (◊A⊃◊B). Suppose that if A had held, B would also have held; the if it is possible for A to hold, it is also possible for B to hold. | |
| From: Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 1) |
| 14531 | Rather than define counterfactuals using necessity, maybe necessity is a special case of counterfactuals [Williamson, by Hale/Hoffmann,A] |
| Full Idea: Instead of regarding counterfactuals as conditionals restricted to a range of possible worlds, we can define the necessity operator by means of counterfactuals. Metaphysical necessity is a special case of ordinary counterfactual thinking. | |
| From: report of Timothy Williamson (Modal Logic within Counterfactual Logic [2010]) by Bob Hale/ Aviv Hoffmann - Introduction to 'Modality' 2 | |
| A reaction: [compressed] I very much like Williamson's approach, of basing these things on the ordinary way that ordinary people think. To me it is a welcome inclusion of psychology into metaphysics, which has been out in the cold since Frege. |
| 6430 | In epistemology we should emphasis the continuity between animal and human minds [Russell] |
| Full Idea: It seems to me desirable in the theory of knowledge to emphasise the continuity between animal and human minds. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.11) | |
| A reaction: I strongly agree with this, mainly because it avoids overemphasis on language in epistemology. It doesn't follow that animals know a lot, and there is a good case for saying that they don't actually 'know' anything, despite having true beliefs. |
| 6441 | Pragmatism judges by effects, but I judge truth by causes [Russell] |
| Full Idea: Pragmatism holds that a belief is to be judged if it has certain effects, whereas I hold that an empirical belief is to be judged true if it has certain kinds of causes. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.15) | |
| A reaction: I'm with Russell here, and this seems to me a convincing objection to pragmatism. The simple problem is that falsehoods can occasionally have very beneficial effects. Beliefs are made true by the facts, not by their consequences. |
| 6431 | Empiricists seem unclear what they mean by 'experience' [Russell] |
| Full Idea: When I began to think about theory of knowledge, I found that none of the philosophers who emphasise 'experience' tells us what they mean by the word. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.11) | |
| A reaction: A very significant comment about empiricism. Hume does not seem very clear about what an 'impression' is. Russell's problem has been dealt with intensively by modern empiricists, who discuss 'the given', and conceptualised perception. |
| 6444 | True belief about the time is not knowledge if I luckily observe a stopped clock at the right moment [Russell] |
| Full Idea: Not all true beliefs are knowledge; the stock example to the contrary is that of a clock which has stopped by which I believe to be going and which I happen to look at when, by chance, it shows the right time. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.15) | |
| A reaction: [in his 1948:112] Russell had spotted Gettier-type problems long before Gettier. The problem of lucky true beliefs dates back to Plato (Idea 2140). This example is also a problem for reliabilism, if the clock is usually working fine. |
| 14628 | Imagination is important, in evaluating possibility and necessity, via counterfactuals [Williamson] |
| Full Idea: Imagination can be made to look cognitively worthless. Once we recall its fallible but vital role in evaluating counterfactual conditionals, we should be more open to the idea that it plays such a role in evaluating claims of possibility and necessity. | |
| From: Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 6) | |
| A reaction: I take this to be a really important idea, because it establishes the importance of imagination within the formal framework of modern analytic philosopher (rather than in the whimsy of poets and dreamers). |
| 14521 | If everything is by necessity, then even denials of necessity are by necessity [Epicurus] |
| Full Idea: He who claims that everything occurs by necessity has no complaint against him who claims that everything does not occur by necessity. For he makes the very claim in question by necessity. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 40) |
| 6433 | Behaviourists struggle to explain memory and imagination, because they won't admit images [Russell] |
| Full Idea: Behaviourists refuse to admit images because they cannot be observed from without, but this causes them difficulties when they attempt to explain either memory or imagination. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.13) | |
| A reaction: This is a striking objection to behaviourism, and it is rarely mentioned in modern discussions of the topic. They might try denying the existence of private 'images', but that wouldn't be very plausible. |
| 6443 | Surprise is a criterion of error [Russell] |
| Full Idea: Surprise is a criterion of error. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.15) | |
| A reaction: Russell is not too precise about this, but it is a nice point. Surprise is thwarted expectation, which implies prior misjudgement. |
| 6427 | Unverifiable propositions about the remote past are still either true or false [Russell] |
| Full Idea: There is no conceivable method by which we can discover whether the proposition 'It snowed on Manhattan Island on the 1st January in the year 1 A.D.' is true or false, but it seems preposterous to maintain that it is neither. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.10) | |
| A reaction: I love this example, which seems so simple and so clear-cut. It criticises verificationism, and gives strong intuitive support for realism, and supports the law of excluded middle. |
| 6435 | You can believe the meaning of a sentence without thinking of the words [Russell] |
| Full Idea: If you have just heard a loud clap of thunder, you believe what is expressed by 'there has just been a loud clap of thunder' even if no words come into your mind. | |
| From: Bertrand Russell (My Philosophical Development [1959], Ch.13) | |
| A reaction: This seems to me important, and accurate. We should not be too mesmerised by language. Animals have beliefs, and this is a nice example of an undeniable non-linguistic human belief. |
| 14522 | What happens to me if I obtain all my desires, and what if I fail? [Epicurus] |
| Full Idea: One should bring this question to bear on all one's desires: what will happen to me if what is sought by desire is achieved, and what will happen if it is not? | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 71) | |
| A reaction: Yet another example of Epicurus moving up a level in his thinking about ethical issues, as in Idea 14517 and Idea 14519. The mark of a true philosopher. This seems to be a key idea for wisdom - to think further ahead than merely what you desire. |
| 3563 | Pleasure and virtue entail one another [Epicurus] |
| Full Idea: It is not possible to live pleasantly without living intelligently and finely and justly, nor to live intelligently and finely and justly without living pleasantly. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 5), quoted by Julia Annas - The Morality of Happiness Ch.16 | |
| A reaction: A person with all these virtues might still suffer from depression. And I don't see why having limited intelligence should stop someone from living pleasantly. Just be warm-hearted. |
| 3560 | Justice is merely a contract about not harming or being harmed [Epicurus] |
| Full Idea: There is no such things as justice in itself; in people's relations with one another in any place and at any time it is a contract about not harming or being harmed. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 33), quoted by Julia Annas - The Morality of Happiness 13.2 |
| 14517 | We value our own character, whatever it is, and we should respect the characters of others [Epicurus] |
| Full Idea: We value our characters as our own personal possessions, whether they are good and envied by men or not. We must regard our neighbours' characters thus too, if they are respectable. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 15) | |
| A reaction: I like this because it introduces a metaethical dimension to the whole problem of virtue. We should value our own character - so should we try to improve it? Should we improve so much as to become unrecognisable? |
| 14513 | Justice is a pledge of mutual protection [Epicurus] |
| Full Idea: The justice of nature is a pledge of reciprocal usefulness, neither to harm one another nor to be harmed. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 31) | |
| A reaction: Notice that justice is not just reciprocal usefulness, but a 'pledge' to that effect. This implies a metaethical value of trust and honesty in keeping the pledge. Is it better to live by the pledge, or to be always spontaneously useful? |
| 14515 | A law is not just if it is not useful in mutual associations [Epicurus] |
| Full Idea: If someone passes a law and it does not turn out to be in accord with what is useful in mutual associations, this no longer possesses the nature of justice. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 37) |
| 14520 | It is small-minded to find many good reasons for suicide [Epicurus] |
| Full Idea: He is utterly small-minded for whom there are many plausible reasons for committing suicide. | |
| From: Epicurus (Principle Doctrines ('Kuriai Doxai') (frags) [c.290 BCE], 38) | |
| A reaction: It is a pity that the insult of 'small-minded' has slipped out of philosophy. The Greeks use it all the time, and know exactly what it means. We all recognise small-mindedness, and it is a great (and subtle) vice. |