12 ideas
| 7823 | Lucretius was rediscovered in 1417 [Grayling] |
| 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] |
| 7809 | In an honour code shame is the supreme punishment, and revenge is a duty [Grayling] |
| 7824 | If suicide is lawful, but assisting suicide is unlawful, powerless people are denied their rights [Grayling] |
| 9425 | Lewis later proposed the axioms at the intersection of the best theories (which may be few) [Mumford on Lewis] |
| 7819 | Religion gives answers, comforts, creates social order, and panders to superstition [Grayling] |
| 7817 | To make an afterlife appealing, this life has to be denigrated [Grayling] |
| 7818 | In Greek mythology only heroes can go to heaven [Grayling] |