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] |
14919 | Empiricists deny what is unobservable, and reject objective modality [Fraassen] |
6783 | To 'accept' a theory is not to believe it, but to believe it empirically adequate [Fraassen, by Bird] |
14917 | To accept a scientific theory, we only need to believe that it is empirically adequate [Fraassen] |
6784 | Why should the true explanation be one of the few we have actually thought of? [Fraassen, by Bird] |
13066 | An explanation is just descriptive information answering a particular question [Fraassen, by Salmon] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |