13 ideas
| 23326 | In the third century Stoicism died out, replaced by Platonism, with Aristotelian ethics [Frede,M] |
| 23335 | In late antiquity nearly all philosophers were monotheists [Frede,M] |
| 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] |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| 23333 | The idea of free will achieved universal acceptance because of Christianity [Frede,M] |
| 23337 | The Stoics needed free will, to allow human choices in a divinely providential cosmos [Frede,M] |
| 23334 | For Christians man has free will by creation in God's image (as in Genesis) [Frede,M] |
| 23336 | There is no will for Plato or Aristotle, because actions come directly from perception of what is good [Frede,M] |
| 9425 | Lewis later proposed the axioms at the intersection of the best theories (which may be few) [Mumford on Lewis] |
| 23313 | The Gnostic demiurge (creator) is deluded, and doesn't care about us [Frede,M] |