11 ideas
| 21054 | Reason enables the unbounded extension of our rules and intentions [Kant] |
| 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] |
| 21053 | The manifest will in the world of phenomena has to conform to the laws of nature [Kant] |
| 20239 | Unlike us, the early Greeks thought envy was a good thing, and hope a bad thing [Hesiod, by Nietzsche] |
| 21055 | Our aim is a constitution which combines maximum freedom with strong restraint [Kant] |
| 21056 | The vitality of business needs maximum freedom (while avoiding harm to others) [Kant] |
| 21057 | The highest ideal of social progress is a universal cosmopolitan existence [Kant] |