Combining Philosophers

All the ideas for Speussipus, Gerhard Gentzen and Albert Casullo

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15 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]
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
594 Speusippus suggested underlying principles for every substance, and ended with a huge list [Speussipus, by Aristotle]
10. Modality / A. Necessity / 11. Denial of Necessity
20475 Maybe modal sentences cannot be true or false [Casullo]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
20476 If the necessary is a priori, so is the contingent, because the same evidence is involved [Casullo]
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
20471 Epistemic a priori conditions concern either the source, defeasibility or strength [Casullo]
20477 The main claim of defenders of the a priori is that some justifications are non-experiential [Casullo]
12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities
20472 Analysis of the a priori by necessity or analyticity addresses the proposition, not the justification [Casullo]
12. Knowledge Sources / A. A Priori Knowledge / 10. A Priori as Subjective
3913 Maybe imagination is the source of a priori justification [Casullo]
13. Knowledge Criteria / A. Justification Problems / 1. Justification / c. Defeasibility
20474 'Overriding' defeaters rule it out, and 'undermining' defeaters weaken in [Casullo]
28. God / C. Attitudes to God / 5. Atheism
2632 Speusippus said things were governed by some animal force rather than the gods [Speussipus, by Cicero]