12 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] |
21899 | There is no being beyond becoming [Deleuze] |
16129 | Evans argues (falsely!) that a contradiction follows from treating objects as vague [Evans, by Lowe] |
16459 | Is it coherent that reality is vague, identities can be vague, and objects can have fuzzy boundaries? [Evans] |
16460 | Evans assumes there can be vague identity statements, and that his proof cannot be right [Evans, by Lewis] |
16457 | There clearly are vague identity statements, and Evans's argument has a false conclusion [Evans, by Lewis] |
14484 | If a=b is indeterminate, then a=/=b, and so there cannot be indeterminate identity [Evans, by Thomasson] |
16224 | There can't be vague identity; a and b must differ, since a, unlike b, is only vaguely the same as b [Evans, by PG] |