21 ideas
| 7548 | Classes, grouped by a convenient property, are logical constructions [Russell] |
| Full Idea: Classes or series of particulars, collected together on account of some property which makes it convenient to be able to speak of them as wholes, are what I call logical constructions or symbolic fictions. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.125) | |
| A reaction: When does a construction become 'logical' instead of arbitrary? What is it about a property that makes it 'convenient'? At this point Russell seems to have built his ontology on classes, and the edifice was crumbling, thanks to Wittgenstein. |
| 7545 | Visible things are physical and external, but only exist when viewed [Russell] |
| Full Idea: I believe that common sense is right in regarding what we see as physical and (in one of several possible senses) outside the mind, but is probably wrong in supposing that it continues to exist when we are no longer looking at it. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.123) | |
| A reaction: This remark (in 1915) is a bit startling from a philosopher well known for his robustly realist stance. Just one of his phases! It seems very counterintuitive - that objects really exist externally, but only when viewed. Schrödinger's Cat? |
| 10993 | Ramsey's Test: believe the consequent if you believe the antecedent [Ramsey, by Read] |
| Full Idea: Ramsey's Test for conditionals is that a conditional should be believed if a belief in its antecedent would commit one to believing its consequent. | |
| From: report of Frank P. Ramsey (Law and Causality [1928]) by Stephen Read - Thinking About Logic Ch.3 | |
| A reaction: A rather pragmatic approach to conditionals |
| 14279 | Asking 'If p, will q?' when p is uncertain, then first add p hypothetically to your knowledge [Ramsey] |
| Full Idea: If two people are arguing 'If p, will q?' and are both in doubt as to p, they are adding p hypothetically to their stock of knowledge, and arguing on that basis about q; ...they are fixing their degrees of belief in q given p. | |
| From: Frank P. Ramsey (Law and Causality [1928], B 155 n) | |
| A reaction: This has become famous as the 'Ramsey Test'. Bennett emphasises that he is not saying that you should actually believe p - you are just trying it for size. The presupposition approach to conditionals seems attractive. Edgington likes 'degrees'. |
| 19419 | Not all of perception is accompanied by consciousness [Leibniz] |
| Full Idea: I do not think that the Cartesians have ever proved or can prove that every perception is accompanied by consciousness. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.195) | |
| A reaction: This idea is very important in Leibniz, because non-conscious or barely conscious thoughts and perceptions explain a huge amount about behaviour, reality and morality. |
| 7553 | Sense-data are purely physical [Russell] |
| Full Idea: Sense-data are purely physical, and all that is mental in connection with them is our awareness of them. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.138) | |
| A reaction: Once this account of sense-data becomes fully clear, it also becomes apparent what a dualist theory it is. The mind is a cinema, I am the audience, and sense-data are the screen. There has to be a big logical gap between viewer and screen. |
| 7549 | If my body literally lost its mind, the object seen when I see a flash would still exist [Russell] |
| Full Idea: My meaning may be made plainer by saying that if my body could remain in exactly the same state in which it is, though my mind had ceased to exist, precisely that object which I now see when I see a flash would exist, though I should not see it. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.126) | |
| A reaction: Zombies, 70 years before Robert Kirk! Sense-data are physical. It is interesting to see a philosopher as committed to empiricism, anti-spiritualism and the priority of science as this, still presenting an essentially dualist picture of perception. |
| 6894 | Mental terms can be replaced in a sentence by a variable and an existential quantifier [Ramsey] |
| Full Idea: Ramsey Sentences are his technique for eliminating theoretical terms in science (and can be applied to mental terms, or to social rights); a term in a sentence is replaced by a variable and an existential quantifier. | |
| From: Frank P. Ramsey (Law and Causality [1928]), quoted by Thomas Mautner - Penguin Dictionary of Philosophy p.469 | |
| A reaction: The technique is used by functionalists and results in a sort of eliminativism. The intrinsic nature of mental states is eliminated, because everything worth saying can be expressed in terms of functional/causal role. Sounds wrong to me. |
| 7546 | A man is a succession of momentary men, bound by continuity and causation [Russell] |
| Full Idea: The real man, I believe, however the police may swear to his identity, is really a series of momentary men, each different one from the other, and bound together, not by a numerical identity, but by continuity and certain instrinsic causal laws. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.124) | |
| A reaction: This seems to be in the tradition of Locke and Parfit, and also follows the temporal-slices idea of physical objects. Personally I take a more physical view of things, and think the police are probably more reliable than Bertrand Russell. |
| 19421 | Souls act as if there were no bodies, and bodies act as if there were no souls [Leibniz] |
| Full Idea: Everything takes place in souls as if there were no body, and everything takes place in bodies as if there were no souls. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.198) | |
| A reaction: I don't think I have ever encountered a modern thinker who accepts this view. Leibniz rejected Occasionalism, but his account depends entirely on the role of God, to set up the pre-established harmony. Why would God do that? |
| 7550 | We could probably, in principle, infer minds from brains, and brains from minds [Russell] |
| Full Idea: It seems not improbable that if we had sufficient knowledge we could infer the state of a man's mind from the state of his brain, or the state of his brain from the state of his mind. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.131) | |
| A reaction: This strikes me as being a very good summary of the claim that mind is reducible to brain, which is the essence of physicalism. Had he been born a little later, Russell would have taken a harder line with physicalism. |
| 19420 | Death and generation are just transformations of an animal, augmented or diminished [Leibniz] |
| Full Idea: Death, like generation, is only the transformation of the same animal, which is sometimes augmented and sometimes diminished. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.195) | |
| A reaction: Leibniz has a very unusual view of death, since neither minds nor their bodies can ever be wholly destroyed. Death is a kind of shrinking. I suspect that he was wrong about that. |
| 19416 | Not all of matter is animated, any more than a pond full of living fish is animated [Leibniz] |
| Full Idea: It must not be said that each portion of matter is animated, just as we do not say that a pond full of fishes is an animated body, although a fish is. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.190) | |
| A reaction: This is a particularly clear picture of the role of monads in matter. Monads are attached to bodies, which are entirely inanimate, but monads suffuse matter and give it its properties, like particularly bubbly champagne. Cf Idea 19422. |
| 19422 | Every particle of matter contains organic bodies [Leibniz] |
| Full Idea: There is no particle of matter which does not contain organic bodies. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.198) | |
| A reaction: Cf Idea 19416. There seems to be an interaction problem here (solved, presumably, by pre-established harmony). The organic bodies are there to explain the active behaviour of matter, but the related matter seems intrinsically inert. |
| 9420 | Causal laws result from the simplest axioms of a complete deductive system [Ramsey] |
| Full Idea: Causal laws are consequences of those propositions which we should take as axioms if we knew everything and organized it as simply as possible in a deductive system. | |
| From: Frank P. Ramsey (Law and Causality [1928], §B) | |
| A reaction: Cf. Idea 9418. |
| 9418 | All knowledge needs systematizing, and the axioms would be the laws of nature [Ramsey] |
| Full Idea: Even if we knew everything, we should still want to systematize our knowledge as a deductive system, and the general axioms in that system would be the fundamental laws of nature. | |
| From: Frank P. Ramsey (Law and Causality [1928], §A) | |
| A reaction: This is the Mill-Ramsey-Lewis view. Cf. Idea 9420. |
| 7551 | Matter is a logical construction [Russell] |
| Full Idea: We must regard matter as a logical construction. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.132) | |
| A reaction: A logical construction is a fancy way of saying a best explanation (but with Ockham's Razor hanging over it). A key component missing from Russell's account is that we can directly experience matter, because we are made of it. |
| 7547 | Matter requires a division into time-corpuscles as well as space-corpuscles [Russell] |
| Full Idea: A true theory of matter requires a division of things into time-corpuscles as well as space-corpuscles. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.125) | |
| A reaction: The division of matter in space seems decidable by physicists, but the division in time seems a bit arbitrary (unless it is quanta of time?). Russell focuses on observable qualities, but are there also intrinsic qualities? |
| 7552 | Six dimensions are needed for a particular, three within its own space, and three to locate that space [Russell] |
| Full Idea: The world of particulars is a six-dimensional space, where six co-ordinates will be required to assign the position of any particular, three to assign its position in its own space, and three to assign the position of its space among the other spaces. | |
| From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.134) | |
| A reaction: Not a proposal that has caught on. One might connect the idea with the notion of 'frames of reference' in Einstein's Special Theory. Inside a frame of reference, three co-ordinates are needed; but where is the frame of reference? |
| 19418 | Mechanics shows that all motion originates in other motion, so there is a Prime Mover [Leibniz] |
| Full Idea: The maxim that there is no motion which has not its origin in another motion, according to the laws of mechanics, leads us again to the Prime Mover. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.194) | |
| A reaction: This is Leibniz's endorsement (uncredited) to Aquinas's First Way. It is hard to see how the laws of mechanics could have anything to say about the origin of movement. And doesn't the law say that the motions of God need a mover? |
| 19417 | All substances are in harmony, even though separate, so they must have one divine cause [Leibniz] |
| Full Idea: My system of Pre-established Harmony furnishes a new proof of God's existence, since it is manifest that the agreement of so many substances, of which the one has no influence upon the other, could only come from a general cause on which they all depend. | |
| From: Gottfried Leibniz (Principle of Life and Plastic Natures [1705], p.192) | |
| A reaction: Adjacent harmony seems self-explanatory, but remote harmony is interesting evidence for God. Hence modern quantum non-locality should make us all wonder whether there is a deeper explanation. |