11 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] |
| 20327 | Modern attention has moved from the intrinsic properties of art to its relational properties [Lamarque/Olson] |
| 20326 | Early 20th cent attempts at defining art focused on significant form, intuition, expression, unity [Lamarque/Olson] |
| 20330 | The dualistic view says works of art are either abstract objects (types), or physical objects [Lamarque/Olson] |
| 5845 | Niceratus learnt the whole of Homer by heart, as a guide to goodness [Xenophon] |
| 5833 | Education is the greatest of human goods [Xenophon] |