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] |
9455 | Maybe proper names have the content of fixing a thing's category [Bealer] |
9454 | The four leading theories of definite descriptions are Frege's, Russell's, Evans's, and Prior's [Bealer] |
13832 | Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking] |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
22668 | Apprehension is a complex intellect grasping the essence of a complex object [Holt,L] |
9453 | Sentences saying the same with the same rigid designators may still express different propositions [Bealer] |
9452 | Propositions might be reduced to functions (worlds to truth values), or ordered sets of properties and relations [Bealer] |
9451 | Modal logic and brain science have reaffirmed traditional belief in propositions [Bealer] |