10 ideas
8378 | Philosophers usually learn science from each other, not from science [Russell] |
Full Idea: Philosophers are too apt to take their views on science from each other, not from science. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.178) | |
A reaction: This wasn't true of Russell, but it is certainly true of me. I rely on philosophical researchers to find the interesting bits of science for me (like blindsight). Memo to myself: read more science. |
16209 | How can point-duration slices of people have beliefs or desires? [Thomson] |
Full Idea: Can one really think that point-duration temporal slices of bodies believe things or want things? | |
From: Judith (Jarvis) Thomson (People and Their Bodies [1997], p.211), quoted by Katherine Hawley - How Things Persist 2.9 n21 | |
A reaction: There is a problem with a slice doing anything long-term. The bottom line is that things are said to 'endure', but that is precisely what time-slices are unable to do. Hawley rejects this idea. |
8375 | 'Necessary' is a predicate of a propositional function, saying it is true for all values of its argument [Russell] |
Full Idea: 'Necessary' is a predicate of a propositional function, meaning that it is true for all possible values of its argument or arguments. Thus 'If x is a man, x is mortal' is necessary, because it is true for any possible value of x. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.175) | |
A reaction: This is presumably the intermediate definition of necessity, prior to modern talk of possible worlds. Since it is a predicate about functions, it is presumably a metalinguistic concept, like the semantic concept of truth. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
4396 | The law of causality is a source of confusion, and should be dropped from philosophy [Russell] |
Full Idea: The law of causality, I believe, like much that passes muster among philosophers, is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.173) | |
A reaction: A bold proposal which should be taken seriously. However, if we drop it from scientific explanation, we may well find ourselves permanently stuck with it in 'folk' explanation. What is the alternative? |
8376 | If causes are contiguous with events, only the last bit is relevant, or the event's timing is baffling [Russell] |
Full Idea: A cause is an event lasting for a finite time, but if cause and effect are contiguous then the earlier part of a changing cause can be altered without altering the effect, and a static cause will exist placidly for some time and then explode into effect. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.177) | |
A reaction: [very compressed] He concludes that they can't be contiguous (and eventually rejects cause entirely). This kind of problem is the sort of thing that only bothers philosophers - the question of how anything can happen at all. Why change? |
8380 | Striking a match causes its igniting, even if it sometimes doesn't work [Russell] |
Full Idea: A may be the cause of B even if there actually are cases of B not following A. Striking a match will be the cause of its igniting, in spite of the fact that some matches are damp and fail to ignite. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.185) | |
A reaction: An important point, although defenders of the constant conjunction view can cope with it. There is a further regularity between dampness of matches and their failure to strike. |
8379 | In causal laws, 'events' must recur, so they have to be universals, not particulars [Russell] |
Full Idea: An 'event' (in a statement of the 'law of causation') is intended to be something that is likely to recur, since otherwise the law becomes trivial. It follows that an 'event' is not some particular, but a universal of which there may be many instances. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.179) | |
A reaction: I am very struck by this. It may be a key insight into understanding what a law of nature actually is. It doesn't follow that we must be realists about universals, but the process of abstraction from particulars is at the heart of generalisation. |
8381 | The constancy of scientific laws rests on differential equations, not on cause and effect [Russell] |
Full Idea: It is not in the sameness of causes and effects that the constancy of scientific law consists, but in sameness of relations. And even 'sameness of relations' is too simple a phrase; 'sameness of differential equations' is the only correct phrase. | |
From: Bertrand Russell (On the Notion of Cause [1912], p.186) | |
A reaction: This seems to be a commitment to the regularity view, since there is nothing more to natural law than that the variables keeping obeying the equations. It also seems to be a very instrumentalist view. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |