6 ideas
18200 | Very large sets should be studied in an 'if-then' spirit [Putnam] |
Full Idea: Sets of a very high type or very high cardinality (higher than the continuum, for example), should today be investigated in an 'if-then' spirit. | |
From: Hilary Putnam (The Philosophy of Logic [1971], p.347), quoted by Penelope Maddy - Naturalism in Mathematics | |
A reaction: Quine says the large sets should be regarded as 'uninterpreted'. |
18199 | Indispensability strongly supports predicative sets, and somewhat supports impredicative sets [Putnam] |
Full Idea: We may say that indispensability is a pretty strong argument for the existence of at least predicative sets, and a pretty strong, but not as strong, argument for the existence of impredicative sets. | |
From: Hilary Putnam (The Philosophy of Logic [1971], p.346), quoted by Penelope Maddy - Naturalism in Mathematics II.2 |
8857 | We must quantify over numbers for science; but that commits us to their existence [Putnam] |
Full Idea: Quantification over mathematical entities is indispensable for science..., therefore we should accept such quantification; but this commits us to accepting the existence of the mathematical entities in question. | |
From: Hilary Putnam (The Philosophy of Logic [1971], p.57), quoted by Stephen Yablo - Apriority and Existence | |
A reaction: I'm not surprised that Hartry Field launched his Fictionalist view of mathematics in response to such a counterintuitive claim. I take it we use numbers to slice up reality the way we use latitude to slice up the globe. No commitment to lines! |
16740 | A power is not a cause, but an aptitude for a cause [Zabarella] |
Full Idea: A power is not the cause of an operation, but only the cause's aptitude for operating. | |
From: Jacob Zabarella (De rebus naturalibus [1590], De fac anim 4:col 692), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 23.5 | |
A reaction: His example is the power of running, which is actually caused by the soul (or whatever), which generates the power. A power is a very superficial thing. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
16571 | Prime matter is exceptionally obscure [Zabarella] |
Full Idea: Nothing in the natural world seems to be more obscure and difficult to grasp than the prime matter of things. | |
From: Jacob Zabarella (De rebus naturalibus [1590], I.1 col 133), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 2.1 | |
A reaction: This spells the beginning of the end for 'prime matter', since a late scholastic is doubting it, even before the scientists got to work. Most modern Aristotelians slide quietly past prime matter, as unhelpful. |