13 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. |
| 10304 | Very few things in set theory remain valid in intuitionist mathematics [Bernays] |
| Full Idea: Very few things in set theory remain valid in intuitionist mathematics. | |
| From: Paul Bernays (On Platonism in Mathematics [1934]) |
| 10303 | Restricted Platonism is just an ideal projection of a domain of thought [Bernays] |
| Full Idea: A restricted Platonism does not claim to be more than, so to speak, an ideal projection of a domain of thought. | |
| From: Paul Bernays (On Platonism in Mathematics [1934], p.261) | |
| A reaction: I have always found Platonism to be congenial when it talks of 'ideals', and ridiculous when it talks of a special form of 'existence'. Ideals only 'exist' because we idealise things. I may declare myself, after all, to be a Restricted Platonist. |
| 10306 | Mathematical abstraction just goes in a different direction from logic [Bernays] |
| Full Idea: Mathematical abstraction does not have a lesser degree than logical abstraction, but rather another direction. | |
| From: Paul Bernays (On Platonism in Mathematics [1934], p.268) | |
| A reaction: His point is that the logicists seem to think that if you increasingly abstract from mathematics, you end up with pure logic. |
| 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? |
| 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. |
| 1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
| Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature. | |
| From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8 |
| 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. |
| 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. |
| 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? |