5 ideas
23025 | Philosophers should be more inductive, and test results by their conclusions, not their self-evidence [Russell] |
Full Idea: The progress of philosophy seems to demand that, like science, it should learn to practise induction, to test its premisses by the conclusions to which they lead, and not merely by their apparent self-evidence. | |
From: Bertrand Russell (Explanations in reply to Mr Bradley [1899], nr end) | |
A reaction: [from Twitter] Love this. It is 'one person's modus ponens is another person's modus tollens'. I think all philosophical conclusions, without exception, should be reached by evaluating the final result fully, and not just following a line of argument. |
9465 | Substitutional universal quantification retains truth for substitution of terms of the same type [Jacquette] |
Full Idea: The substitutional interpretation says the universal quantifier is true just in case it remains true for all substitutions of terms of the same type as that of the universally bound variable. | |
From: Dale Jacquette (Intro to III: Quantifiers [2002], p.143) | |
A reaction: This doesn't seem to tell us how it gets started with being true. |
9466 | Nominalists like substitutional quantification to avoid the metaphysics of objects [Jacquette] |
Full Idea: Some substitutional quantificationists in logic hope to avoid philosophical entanglements about the metaphysics of objects, ..and nominalists can find aid and comfort there. | |
From: Dale Jacquette (Intro to III: Quantifiers [2002], p.143) | |
A reaction: This has an appeal for me, particularly if it avoids abstract objects, but I don't see much problem with material objects, so we might as well have a view that admits those. |
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. |
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. |