21 ideas
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall] |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
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] |
11065 | The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna] |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
7630 | Ryle's dichotomy between knowing how and knowing that is too simplistic [Maund] |
7632 | Perception is sensation-then-concept, or direct-concepts, or sensation-saturated-in-concepts [Maund] |
7635 | Sense-data have an epistemological purpose (foundations) and a metaphysical purpose (explanation) [Maund] |
7638 | One thesis says we are not aware of qualia, but only of objects and their qualities [Maund] |
7642 | The Myth of the Given claims that thought is rationally supported by non-conceptual experiences [Maund] |
7640 | Mountains are adverbial modifications of the earth, but still have object-characteristics [Maund] |
7641 | Adverbialism tries to avoid sense-data and preserve direct realism [Maund] |
7637 | Thought content is either satisfaction conditions, or exercise of concepts [Maund, by PG] |