3 ideas
15716 | If axioms and their implications have no contradictions, they pass my criterion of truth and existence [Hilbert] |
Full Idea: If the arbitrarily given axioms do not contradict each other with all their consequences, then they are true and the things defined by the axioms exist. For me this is the criterion of truth and existence. | |
From: David Hilbert (Letter to Frege 29.12.1899 [1899]), quoted by R Kaplan / E Kaplan - The Art of the Infinite 2 'Mind' | |
A reaction: If an axiom says something equivalent to 'fairies exist, but they are totally undetectable', this would seem to avoid contradiction with anything, and hence be true. Hilbert's idea sounds crazy to me. He developed full Formalism later. |
1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature. | |
From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8 |
13097 | Force in substance makes state follow state, and ensures the very existence of substance [Leibniz] |
Full Idea: By the force I give to substances, I understand a state from which another state follows, if nothing prevents it. ...I dare say that without force, there would be no substance. | |
From: Gottfried Leibniz (Letters to Lelong [1712], 1712), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 7.1 | |
A reaction: [the whole quote is interesting] This remark, more than any other I have found, places force at the centre of Leibniz's metaphysics. He is using it to resist Spinoza's one-substance view. |