18 ideas
| 11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
| 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] |
| 13832 | Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking] |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| 6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
| 8388 | Causation is either direct realism, Humean reduction, non-Humean reduction or theoretical realism [Tooley] |
| 8389 | Causation distinctions: reductionism/realism; Humean/non-Humean states; observable/non-observable [Tooley] |
| 8416 | Reductionists can't explain accidents, uninstantiated laws, probabilities, or the existence of any laws [Tooley] |
| 8393 | We can only reduce the direction of causation to the direction of time if we are realist about the latter [Tooley] |
| 8390 | Causation is directly observable in pressure on one's body, and in willed action [Tooley] |
| 8418 | Quantum physics suggests that the basic laws of nature are probabilistic [Tooley] |
| 8392 | Probabilist laws are compatible with effects always or never happening [Tooley] |
| 8399 | The actual cause may not be the most efficacious one [Tooley] |
| 8391 | In counterfactual worlds there are laws with no instances, so laws aren't supervenient on actuality [Tooley] |
| 8394 | Explaining causation in terms of laws can't explain the direction of causation [Tooley] |
| 8398 | Causation is a concept of a relation the same in all worlds, so it can't be a physical process [Tooley] |