12 ideas
9456 | Modal logic is multiple systems, shown in the variety of accessibility relations between worlds [Jacquette] |
9457 | The two main views in philosophy of logic are extensionalism and intensionalism [Jacquette] |
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] |
9458 | Extensionalists say that quantifiers presuppose the existence of their objects [Jacquette] |
9461 | Intensionalists say meaning is determined by the possession of properties [Jacquette] |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
9460 | Extensionalist semantics forbids reference to nonexistent objects [Jacquette] |
9459 | Extensionalist semantics is circular, as we must know the extension before assessing 'Fa' [Jacquette] |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |