13 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] |
| 21642 | If quantification is all substitutional, there is no ontology [Quine] |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| 1633 | Absolute ontological questions are meaningless, because the answers are circular definitions [Quine] |
| 18964 | Ontology is relative to both a background theory and a translation manual [Quine] |
| 18965 | We know what things are by distinguishing them, so identity is part of ontology [Quine] |
| 1634 | Two things are relative - the background theory, and translating the object theory into the background theory [Quine] |
| 16383 | Puzzled Pierre has two mental files about the same object [Recanati on Kripke] |
| 8470 | Reference is inscrutable, because we cannot choose between theories of numbers [Quine, by Orenstein] |
| 18963 | Indeterminacy translating 'rabbit' depends on translating individuation terms [Quine] |