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] |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
13160 | To exist and be understood, a multitude must first be reduced to a unity [Leibniz] |
13161 | Substances are everywhere in matter, like points in a line [Leibniz] |
21515 | Incoherence may be more important for enquiry than coherence [Olsson] |
21514 | Coherence is the capacity to answer objections [Olsson] |
21496 | Mere agreement of testimonies is not enough to make truth very likely [Olsson] |
21499 | Coherence is only needed if the information sources are not fully reliable [Olsson] |
21502 | A purely coherent theory cannot be true of the world without some contact with the world [Olsson] |
21512 | Extending a system makes it less probable, so extending coherence can't make it more probable [Olsson] |