22 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. |
| 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? |
| 4316 | Either all action is rational, or reason dominates, or reason is only concerned with means [Cottingham] |
| Full Idea: We can distinguish rational exclusivism (all activity is guided by reason - Plato and Spinoza), rational hegemonism (all action is dominated by reason), and rational instrumentalism (reason assesses means rather than ends - Hume). | |
| From: John Cottingham (Reason, Emotions and Good Life [2000]) | |
| A reaction: The idea that reason is the only cause of actions seems deeply implausible, but I strongly resist Hume's instrumental approach. Action without desire is not a contradiction. |
| 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. |
| 7602 | In the Bible God changes his mind (repenting of creating humanity, in the Flood) [Armstrong,K] |
| Full Idea: In the Bible God changes his mind, as when he repents of having made man and decides to destroy the human race in the Flood. | |
| From: Karen Armstrong (A History of God [1993], Ch.1) | |
| A reaction: It becomes apparent that the most startling feature of Christian fundamentalism is its uncritical reading of the Bible, in which passages are wilfully lifted from context, and inconvenient inconsistencies are ruthlessly ignored. |
| 7605 | Monotheism introduced intolerance into religious thinking [Armstrong,K] |
| Full Idea: We have become so used to the intolerance of monotheism that we may not appreciate that its hostility towards other gods was a new religious attitude; paganism was an essentially tolerant faith. | |
| From: Karen Armstrong (A History of God [1993], Ch.2) | |
| A reaction: The comedian Dave Allen always signed off with "may your god go with you". To me the most striking feature of monotheists is frequently their barely controlled aggression, beneath a mask of strained compassion. |
| 7599 | Around 800 BCE teachers superseded gods in India [Armstrong,K] |
| Full Idea: Around the eighth century BCE the gods ceased to be very important in India, and would be superseded by the religious teacher, who would be considered higher than the gods. | |
| From: Karen Armstrong (A History of God [1993], Ch.1) | |
| A reaction: At least there has been one culture that gave an appropriate status to teachers. It seems astonishing in that age that human beings could have higher status than gods - way before the European 'humanists'. |
| 7597 | There is virtually no sign of monotheism in the Pentateuch [Armstrong,K] |
| Full Idea: It is very difficult to find a single monotheistic statement in the whole of the Pentateuch, and even the Ten Commandments take the existence of other gods for granted ("There shall be no strange gods for you before my face"). | |
| From: Karen Armstrong (A History of God [1993], Ch.1) | |
| A reaction: The transition from polytheism to monotheism is very strange. First God is 'jealous' of other gods, then supremely above them, and eventually totally exclusive. It's like watching the rise of Stalin. |
| 7606 | The idea that Jesus was God was only settled in the fourth century [Armstrong,K] |
| Full Idea: Jesus himself certainly never claimed to be God, and the doctrine that Jesus had been God in human form was not finalised until the fourth century. | |
| From: Karen Armstrong (A History of God [1993], Ch.3) | |
| A reaction: It was this final view which seems to have provoked Muhammed into developing a religion with the slogan "there is only one God". In Christianity an initially promising set of teachings grew into a prolonged irrational hysteria. |
| 7596 | Faith is not just belief in propositions, but also putting trust in them [Armstrong,K] |
| Full Idea: There is a distinction between belief in a set of propositions and a faith which enables us to put our trust in them. | |
| From: Karen Armstrong (A History of God [1993], Intro) | |
| A reaction: This is interestingly distinct from the usual idea that faith is putting belief in propositions which are not sufficiently rationally justified. How many philosophers actually have faith in the propositions they say they believe? |