10 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] |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| 16641 | Whiteness does not exist, but by it something can exist-as-white [Aquinas] |
| 22170 | Senses grasp external properties, but the understanding grasps the essential natures of things [Aquinas] |
| 22169 | Initial universal truths are present within us as potential, to be drawn out by reason [Aquinas] |
| 22168 | Minds take in a likeness of things, which activates an awaiting potential [Aquinas] |
| 15664 | Ideology is 'socially necessary illusion' or 'socially necessary false-consciousness' [Adorno, by Finlayson] |