Combining Philosophers

All the ideas for H.Putnam/P.Oppenheim, Gerhard Gentzen and Albert of Saxony

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11 ideas

5. Theory of Logic / A. Overview of Logic / 2. History of Logic
11022 Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
11065 The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna]
11023 The logical connectives are 'defined' by their introduction rules [Gentzen]
11213 Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen]
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 / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
10067 Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave]
7. Existence / A. Nature of Existence / 2. Types of Existence
16664 Everything that exists is either a substance or an accident [Albert of Saxony]
9. Objects / E. Objects over Time / 6. Successive Things
16703 God could make a successive thing so that previous parts cease to exist [Albert of Saxony]
16699 Successive entities just need parts to succeed one another, without their existence [Albert of Saxony]
14. Science / D. Explanation / 2. Types of Explanation / j. Explanations by reduction
20653 Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
16570 Elements are found last in dismantling bodies, and first in generating them [Albert of Saxony]