5 ideas
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. |
10710 | We accept substance, to avoid infinite backwards chains of meaning [Wittgenstein, by Potter] |
Full Idea: Wittgenstein is the most renowned modern proponent of substance, and argued that sense must be determinate ...and that any conceptual scheme which genuinely represents a world cannot contain infinite backward chains of meaning. | |
From: report of Ludwig Wittgenstein (works [1935]) by Michael Potter - Set Theory and Its Philosophy 03.3 | |
A reaction: This is a key idea for explaining the somewhat surprising revival of the notion of substance in modern times, when it appeared to have been buried by atomism in the seventeenth century. The new argument is a semantic one. |
1590 | The just man does not harm his enemies, but benefits everyone [Plato] |
Full Idea: First, Socrates, you told me justice is harming your enemies and helping your friends. But later it seemed that the just man, since everything he does is for someone's benefit, never harms anyone. | |
From: Plato (Clitophon [c.372 BCE], 410b) | |
A reaction: Socrates certainly didn't subscribe to the first view, which is the traditional consensus in Greek culture. In general Socrates agreed with the views later promoted by Jesus. |