26 ideas
16477 | Asserting not-p is saying p is false [Russell] |
Full Idea: When you do what a logician would call 'asserting not-p', you are saying 'p is false'. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: This is presumably classical logic. If we could label p as 'undetermined' (a third truth value), then 'not-p' might equally mean 'undetermined'. |
16484 | There are four experiences that lead us to talk of 'some' things [Russell] |
Full Idea: Propositions about 'some' arise, in practice, in four ways: as generalisations of disjunctions; when an instance suggests compatibility of terms we thought incompatible; as steps to a generalisation; and in cases of imperfect memory. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: Modern logicians seem to have no interest in the question Russell is investigating here, but I love his attempt, however vague the result, to connect logic to real experience and thought. |
18170 | The Axiom of Reducibility is self-effacing: if true, it isn't needed [Quine] |
Full Idea: The Axiom of Reducibility is self-effacing: if it is true, the ramification it is meant to cope with was pointless to begin with. | |
From: Willard Quine (Introduction to Russell's Theory of Types [1967], p.152), quoted by Penelope Maddy - Naturalism in Mathematics I.1 | |
A reaction: Maddy says the rejection of Reducibility collapsed the ramified theory of types into the simple theory. |
16486 | The physical world doesn't need logic, but the mental world does [Russell] |
Full Idea: The non-mental world can be completely described without the use of any logical word, …but when it comes to the mental world, there are facts which cannot be mentioned without the use of logical words. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: He adds that logical words are not needed for physics, but are needed for psychology. I love Russell's interest in the psychology of logic (in defiance of the anti-psychologism of Frege). See also the ideas of Robert Hanna. |
2947 | Questions wouldn't lead anywhere without the law of excluded middle [Russell] |
Full Idea: Without the law of excluded middle, we could not ask the questions that give rise to discoveries. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], c.p.88) |
16480 | A disjunction expresses indecision [Russell] |
Full Idea: A disjunction is the verbal expression of indecision, or, if a question, of the desire to reach a decision. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: Russell is fishing here for Grice's conversational implicature. If you want to assert a simple proposition, you don't introduce it into an irrelevant disjunction, because that would have a particular expressive purpose. |
16479 | 'Or' expresses hesitation, in a dog at a crossroads, or birds risking grabbing crumbs [Russell] |
Full Idea: Psychologically, 'or' corresponds to a state of hesitation. A dog waits at a fork in the road, to see which way you are going. For crumbs on a windowsill, birds behave in a manner we would express by 'shall I be brave, or go hungry?'. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: I love two facts here - first, that Russell wants to link the connective to the psychology of experience, and second, that a great logician wants to connect his logic to the minds of animals. |
16481 | 'Or' expresses a mental state, not something about the world [Russell] |
Full Idea: When we assert 'p or q' we are in a state which is derivative from two previous states, and we express this state, not something about the world. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: His example: at a junction this road or that road goes to Oxford, but the world only contains the roads, not some state of 'this or that road'. He doesn't deny that in one sense 'p or q' tells you something about the world. |
16487 | Maybe the 'or' used to describe mental states is not the 'or' of logic [Russell] |
Full Idea: It might be contended that, in describing what happens when a man believes 'p or q', the 'or' that we must use is not the same as the 'or' of logic. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: This seems to be the general verdict on Russell's enquiries in this chapter, but I love any attempt, however lacking in rigour etc., to connect formal logic to how we think, and thence to the world. |
16483 | Disjunction may also arise in practice if there is imperfect memory. [Russell] |
Full Idea: Another situation in which a disjunction may arise is practice is imperfect memory. 'Either Brown or Jones told me that'. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) |
16475 | A 'heterological' predicate can't be predicated of itself; so is 'heterological' heterological? Yes=no! [Russell] |
Full Idea: A predicate is 'heterological' when it cannot be predicated of itself; thus 'long' is heterological because it is not a long word, but 'short' is homological. So is 'heterological' heterological? Either answer leads to a contradiction. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: [Grelling's Paradox] Yes: 'heterological' is heterological because it isn't heterological; No: it isn't, because it is. Russell says we therefore need a hierarchy of languages (types), and the word 'word' is outside the system. |
16482 | All our knowledge (if verbal) is general, because all sentences contain general words [Russell] |
Full Idea: All our knowledge about the world, in so far as it is expressed in words, is more or less general, because every sentence contains at least one word that is not a proper name, and all such words are general. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: I really like this, especially because it addresses the excessive reliance of some essentialists on sortals, categories and natural kinds, instead of focusing on the actual physical essences of individual objects. |
4758 | Naïve realism leads to physics, but physics then shows that naïve realism is false [Russell] |
Full Idea: Naïve realism leads to physics, and physics, if true, shows that naïve realism is false. Therefore naïve realism, if true, is false, therefore it is false. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], p.13) | |
A reaction: I'm inclined to agree with this, though once you have gone off and explored representation and sense data you may be driven back to naïve realism again. |
16476 | For simple words, a single experience can show that they are true [Russell] |
Full Idea: So long as a man avoids words which are condensed inductions (such as 'dog'), and confines himself to words that can describe a single experience, it is possible for a single experience to show that his words are true. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: One might question whether a line can be drawn between the inductive and the non-inductive in this way. I'm inclined just to say that the simpler the proposition the less room there is for error in confirming it. |
16485 | Perception can't prove universal generalisations, so abandon them, or abandon empiricism? [Russell] |
Full Idea: Propositions about 'some' may be proved empirically, but propositions about 'all' are difficult to know, and can't be proved unless such propositions are in the premisses. These aren't in perception, so forgo general propositions, or abandon empiricism? | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: This is obviously related to the difficulty empiricists have with induction. You could hardly persuade logicians to give up the universal quantifier, because it is needed in mathematics. Do we actually know any universal empirical truths? |
16478 | A mother cat is paralysed if equidistant between two needy kittens [Russell] |
Full Idea: I once, to test the story of Buridan's Ass, put a cat exactly half-way between her two kittens, both too young to move: for a time she found the disjunction paralysing. | |
From: Bertrand Russell (An Inquiry into Meaning and Truth [1940], 5) | |
A reaction: Buridan's Ass is said to have starved between two equal piles of hay. Reason can't be the tie-breaker; reason obviously says 'choose one!', but intellectualism demands a reason for the one you choose. |
8239 | If the King likes music then there is hope for the state [Mengzi (Mencius)] |
Full Idea: If the King has a great fondness for music, then perhaps there is hope for the state of Ch'i. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.B.1) | |
A reaction: This seems to be Shakespeare's attitude to music as well. The general idea must be that love of music requires a selfless state of mind, where the mind revels in the beauty of something outside of itself. Respect is the desirable result. |
23398 | Human nature is naturally compassionate and good (as a 'sprout'), but people may not be good [Mengzi (Mencius), by Norden] |
Full Idea: Mengzi does not claim that humans are innately good; he claims that human nature is innately good. …He says that 'the heart of compassion' (manifested when anyone sees a child about to fall into a well) is the 'sprout of benevolence'. | |
From: report of Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE]) by Bryan van Norden - Intro to Classical Chinese Philosophy 6.II | |
A reaction: There is a nice distinction here between the 'sprout' of human nature and the finished product. Seeds have the potential to produce tall healthy plants, but circumstances can warp them. |
23400 | Righteousness is extending the unthinkable, to reveal what must be done [Mengzi (Mencius)] |
Full Idea: People all have things they will not do. To extend this reaction to that which they will do is righteousness. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 7B31), quoted by Bryan van Norden - Intro to Classical Chinese Philosophy 6.IV | |
A reaction: Very nice! Kekes points out the enormous importance of unthinkable deeds. Depravity is when the unthinkable gradually begins to look possible, which is probably a social phenomenon, a creeping cancer in a culture. |
23399 | Each correct feeling relies on an underlying virtue [Mengzi (Mencius)] |
Full Idea: The heart of compassion is benevolence. The heart of disdain is righteousness. The heart of respect is propriety. The heart of approval and disapproval is wisdom. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 6A6), quoted by Bryan van Norden - Intro to Classical Chinese Philosophy 6.III | |
A reaction: 'Disdain' seems to be the response to anyone who is disrespectful. Note that wisdom concerns judgements. Respect seems to be more of a social convention than an actual concern for others. |
8235 | Should a coward who ran fifty paces from a battle laugh at another who ran a hundred? [Mengzi (Mencius)] |
Full Idea: If two soldiers were fleeing from a battle, and one stopped after a hundred paces and the other stopped after a fifty paces, what would you think if the latter, as one who only ran fifty paces, were to laugh at the former who ran a hundred? | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.A.3) | |
A reaction: A nice illustration, in my view, of the universality of truths about human virtue. In no culture would this laughter be appropriate. Nevertheless, there must be degrees of dishonour. Better to flee than join in with the likely winners. |
8240 | A true king shares his pleasure with the people [Mengzi (Mencius)] |
Full Idea: If you shared your enjoyment of music or of hunting with the people, you would be a true King. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.B.1) | |
A reaction: I suspect that this is a great truth for dictators and traditional monarchs. One pictures the successful ones attending public entertainments, and allowing the public to see their own. Tyrants keep entertainment private. Nero is a counterexample! |
8237 | Extend the treatment of the old and young in your family to the rest of society [Mengzi (Mencius)] |
Full Idea: Treat the aged of your own family in a manner befitting their venerable age and extend this treatment to the aged of other families. Treat your own young in a manner befitting their tender age, and extend this to the young of other families. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.A.7) | |
A reaction: This seems to me to articulate the ideal of communitarianism very nicely. Morality is not just about healthy adults in war and peace. It must include the children and the old. The values of the family are above the values of contracts and calculations. |
8241 | Only put someone to death if the whole population believes it is deserved [Mengzi (Mencius)] |
Full Idea: When close attendants say a man deserves death, do not listen; when all the councillors say so, do not listen; when everyone says so, have the case investigated. If he is guilty, put him to death; he was put to death by the whole country. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.B.7) | |
A reaction: The jury system is a gesture in this direction. Compare Idea 95. In Mencius's time, no doubt, everyone believed that capital punishment was sometimes right. Nowadays, when many people (e.g. me) reject it, the procedure won't work. |
8238 | Seeking peace through war is like looking for fish up a tree [Mengzi (Mencius)] |
Full Idea: Your desire to extend your territory by war, in order to bring peace, is like looking for fish by climbing a tree. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.A.7) | |
A reaction: Mencius had a flair for analogies. Just occasionally I suppose he might be wrong on this point, but I would think that experiments in the laboratory of history have shown that he is right in nearly all cases. |
8236 | Avoid the animals you are going to eat, as it is hard once you have got to know them [Mengzi (Mencius)] |
Full Idea: Once a gentleman has seen animals alive, he cannot bear to see them die, and once having heard their cry, he cannot bear to eat their flesh. That is why the gentleman keeps his distance from the kitchen. | |
From: Mengzi (Mencius) (The Mengzi (Mencius) [c.332 BCE], 1.A.7) | |
A reaction: If you applied this to a Gestapo officer and his victims, it would obviously be the epitome of wickedness. But it is complex. Compassion is expected when we encounter suffering, but we are not obliged to seek out suffering. Or are we? |