8 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. |
12270 | Being is one [Melissus, by Aristotle] |
Full Idea: Being is one. | |
From: report of Melissus (fragments/reports [c.443 BCE]) by Aristotle - Topics 104b23 | |
A reaction: I can only really understand this in terms of physics, as the belief that ultimately there is one simple theory which explains everything. That project doesn't look terribly promising, despite the lovely simplifications of modern physics. |
7006 | Observing irrelevant items supports both 'all x are y' and 'all x are non-y', revealing its absurdity [Schofield,J] |
Full Idea: Although Hempel's raven paradox produces an absurdity of irrelevant observations, we can ignore it because (unlike good observations) observing a white handbag supports the contradictions of 'ravens are black' and 'ravens are non-black'. | |
From: Jonathan Schofield (talk [2005]), quoted by PG - Db (ideas) | |
A reaction: The idea of 'eliminating it from our enquiries' cannot be totally irrational (e.g. in detective work), but it is only seriously sensible in a restricted domain (such as a country house) |
3059 | There is no real motion, only the appearance of it [Melissus, by Diog. Laertius] |
Full Idea: There is no such thing as real motion, but there only appears to be such. | |
From: report of Melissus (fragments/reports [c.443 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.4.3 |
5100 | The void is not required for change, because a plenum can alter in quality [Aristotle on Melissus] |
Full Idea: There is no need for void to be the cause of all change, because it is perfectly possible for a plenum to alter qualitatively (which is something Melissus overlooked). | |
From: comment on Melissus (fragments/reports [c.443 BCE]) by Aristotle - Physics 214a27 | |
A reaction: In modern physics this presumably gives us fluctuations in a force field. Motion is like a cat being digested by a python. The atomist claim that emptiness is needed if anything is to move still has intuitive appeal. |
456 | Nothing could come out of nothing [Melissus] |
Full Idea: If Nothing existed, in no way could anything come into being out of nothing. | |
From: Melissus (fragments/reports [c.443 BCE], B1), quoted by (who?) - where? |