Combining Texts

All the ideas for 'Problems in Personal Identity', 'Letters to Samuel Masson' and 'works'

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

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4 ideas

5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic

3299	In logic identity involves reflexivity (x=x), symmetry (if x=y, then y=x) and transitivity (if x=y and y=z, then x=z) [Baillie]

6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite

13190

I don't admit infinite numbers, and consider infinitesimals to be useful fictions [Leibniz]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers

3338	Numbers have been defined in terms of 'successors' to the concept of 'zero' [Peano, by Blackburn]

6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic

5897	0 is a non-successor number, all successors are numbers, successors can't duplicate, if P(n) and P(n+1) then P(all-n) [Peano, by Flew]