Combining Texts

All the ideas for '', 'What is an Idea?' and 'Principles of Theoretical Logic'

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6 ideas

4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC

17750

The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki]

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic

11211

If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]

5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives

11210

Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]

11212

The sense of a connective comes from primitively obvious rules of inference [Rumfitt]

18. Thought / C. Content / 2. Ideas

19423

By an 'idea' I mean not an actual thought, but the resources we can draw on to think [Leibniz]

19. Language / F. Communication / 3. Denial

11214

We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]