4 ideas
15927 | Definition just needs negation, known variables, conjunction, disjunction, substitution and quantification [Weyl, by Lavine] |
490 | Everything happens by reason and necessity [Leucippus] |
20919 | How can things without weight compose weight? [Alexander] |
10246 | The limit of science is isomorphism of theories, with essences a matter of indifference [Weyl] |