Combining Texts

All the ideas for 'fragments/reports', 'Sets, Aggregates and Numbers' and 'Investigations into Logical Deduction'

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7 ideas

5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
13832 Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
17818 How many? must first partition an aggregate into sets, and then logic fixes its number [Yourgrau]
17822 Nothing is 'intrinsically' numbered [Yourgrau]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
17817 Defining 'three' as the principle of collection or property of threes explains set theory definitions [Yourgrau]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
17815 We can't use sets as foundations for mathematics if we must await results from the upper reaches [Yourgrau]
17821 You can ask all sorts of numerical questions about any one given set [Yourgrau]
23. Ethics / A. Egoism / 1. Ethical Egoism
3031 The greatest good is not the achievement of desire, but to desire what is proper [Menedemus, by Diog. Laertius]