Combining Texts

All the ideas for 'fragments/reports', 'Letters to Samuel Masson' and 'What is Mathematical Truth?'

unexpand these ideas     |    start again     |     specify just one area for these texts


3 ideas

6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
I don't admit infinite numbers, and consider infinitesimals to be useful fictions [Leibniz]
     Full Idea: Notwithstanding my infinitesimal calculus, I do not admit any real infinite numbers, even though I confess that the multitude of things surpasses any finite number, or rather any number. ..I consider infinitesimal quantities to be useful fictions.
     From: Gottfried Leibniz (Letters to Samuel Masson [1716], 1716)
     A reaction: With the phrase 'useful fictions' we seem to have jumped straight into Harty Field. I'm with Leibniz on this one. The history of mathematics is a series of ingenious inventions, whenever they seem to make further exciting proofs possible.
10. Modality / B. Possibility / 1. Possibility
Mathematics eliminates possibility, as being simultaneous actuality in sets [Putnam]
     Full Idea: Mathematics has got rid of possibility by simply assuming that, up to isomorphism anyway, all possibilities are simultaneous actual - actual, that is, in the universe of 'sets'.
     From: Hilary Putnam (What is Mathematical Truth? [1975], p.70), quoted by Stewart Shapiro - Philosophy of Mathematics 7.5
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
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?