Combining Philosophers

All the ideas for Jacques Lenfant, Karl Weierstrass and Dag Prawitz

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8 ideas

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

13831

Logic is based on transitions between sentences [Prawitz]

5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence

13827

Logical consequence isn't a black box (Tarski's approach); we should explain how arguments work [Prawitz]

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

13825

Natural deduction introduction rules may represent 'definitions' of logical connectives [Prawitz]

5. Theory of Logic / H. Proof Systems / 4. Natural Deduction

13823

In natural deduction, inferences are atomic steps involving just one logical constant [Prawitz]

5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models

13826

Model theory looks at valid sentences and consequence, but not how we know these things [Prawitz]

6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals

18086

Weierstrass eliminated talk of infinitesimals [Weierstrass, by Kitcher]

6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits

18092

Weierstrass made limits central, but the existence of limits still needed to be proved [Weierstrass, by Bostock]

8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence

12750

The question is whether force is self-sufficient in bodies, and essential, or dependent on something [Lenfant]