25 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. |
| 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. |
| 527 | Everything exists which anyone perceives [Metrodorus of Chios] |
| Full Idea: Everything exists which anyone perceives. | |
| From: Metrodorus (Chi) (Natural Science (lost) [c.340 BCE], B2), quoted by (who?) - where? | |
| A reaction: cf Berkeley and Epicurus. This misses out the problem of perceptual error, such as a square tower looking round from a distance, or one person in a group thinking they have seen something. It is still a good criterion, though! |
| 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. |
| 7404 | Nations are not obliged to help one-another, but are obliged not to harm one another [Grotius, by Tuck] |
| Full Idea: Grotius explored the implications of the idea that nation-states were under no obligation to help one another, but they were obliged not to harm each other. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Richard Tuck - Hobbes Ch.1 | |
| A reaction: This is quite a striking disanalogy between accepted personal morality and political morality. There are signs in recent years of some recognition that other nations should not just sit and watch suffering. |
| 7402 | Everyone has a right of self-preservation, and harming others is usually unjustifiable [Grotius, by Tuck] |
| Full Idea: Grotius said that all men would agree that everyone has a fundamental right to preserve themselves, and that wanton or unnecessary injury to another person is unjustifiable. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Richard Tuck - Hobbes Ch.1 | |
| A reaction: Who cares if it is 'justifiable'? Do I have to 'justify' killing a mosquito if it lands on my arm? Grotius is taking a step beyond saying that people should defend themselves, to say that they have a 'right' to - the only truly basic right. |
| 21938 | Democracy needs respect for individuality, but the 'community of friends' implies strict equality [Grotius] |
| Full Idea: There is no democracy without respect for irreducible singularity, but there is no democracy with the 'community of friends' without the calculation of majorities, without identifiable representable subjects, all equal. | |
| From: Hugo Grotius (On the Law of War and Peace [1625]), quoted by Simon Glendinning - Derrida: A Very Short Introduction 7 | |
| A reaction: [source not given] Derrida calls this conflict 'tragic'. The obvious reply is that equality is not an absolute. We can be equal in voting rights while being unequal in height or musical talent. |
| 19845 | A person is free to renounce their state, as long as it is not a moment of crisis [Grotius, by Rousseau] |
| Full Idea: Grotius thinks that each person can renounce his state and leave the country. (n15: provided it is not to evade one's duty the moment the homeland needs us; this would be criminal and punishable; it would not be withdrawal, but desertion) | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Jean-Jacques Rousseau - The Social Contract (tr Cress) III.18 | |
| A reaction: The obvious example is Britons going to America in 1939, or (more controversially) conscripts going to Canada to avoid fighting in Vietnam. I'm unclear whether the idea in the note is that of Grotius or of Rousseau). Is tax exile OK, then? |
| 22133 | Grotius and Pufendorf based natural law on real (rather than idealised) humanity [Grotius, by Ford,JD] |
| Full Idea: Grotius and Pufendorf transformed the natural law tradition by starting from identifiable traits of human nature rather than ideas about what human beings ought to be. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by J.D. Ford - Pufendorf, Samuel p.863 |
| 7406 | A natural right of self-preservation is balanced by a natural law to avoid unnecessary harm [Grotius, by Tuck] |
| Full Idea: For Grotius, there was a fundamental 'natural right' of self-preservation upon which all known moralities and codes of social behaviour must have been constructed, but it is balanced by a fundament duty or 'natural law' to abstain from harming others. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Richard Tuck - Hobbes Ch.2 | |
| A reaction: This theory has the virtue of economy, but I don't see how you can clearly justify those particular natural rights and laws, without allowing others to creep in, such as a right to a decent share of food, or a law requiring some fairness. |
| 7403 | Grotius ignored elaborate natural law theories, preferring a basic right of self-preservation [Grotius, by Tuck] |
| Full Idea: Grotius said there was a minimum core of morality (based on self-preservation), and disregarded the elaborate accounts of principles of natural law which Aristotelians had always sought to develop. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Richard Tuck - Hobbes Ch.1 | |
| A reaction: Aquinas would be the key Aristotelian here. I tend towards the Aristotelian view. If you go for the minimal view, it is not clear why there is a 'right' to self-preservation, rather than a mere desire for it. |
| 23585 | It is permissible in a just cause to capture a place in neutral territory [Grotius] |
| Full Idea: It is permissible for one who is waging a just war to take possession of a place situated in a country free from hostilities. | |
| From: Hugo Grotius (On the Law of War and Peace [1625], II.ii.x), quoted by Michael Walzer - Just and Unjust Wars 15 n | |
| A reaction: This rejects Combatant Equality, allowing the just to do what is morally forbidden to the unjust. |
| 6892 | Moral principles have some validity without a God commanding obedience [Grotius, by Mautner] |
| Full Idea: In the Prolegomena to his work there is a famous statement that moral principles laid down in the work would have some degree of validity even if there was no God commanding obedience. | |
| From: report of Hugo Grotius (On the Law of War and Peace [1625]) by Thomas Mautner - Penguin Dictionary of Philosophy p.229 | |
| A reaction: I am not clear why Grotius felt obliged to qualify his claim with the phrase 'some degree'. I don't see how God's command can affect the 'validity' of morality, or how there can be a middle ground between dependence on and independence of God. |