6 ideas
17832 | Zermelo showed that the ZF axioms in 1930 were non-categorical [Zermelo, by Hallett,M] |
13028 | Replacement was added when some advanced theorems seemed to need it [Zermelo, by Maddy] |
17626 | The antinomy of endless advance and of completion is resolved in well-ordered transfinite numbers [Zermelo] |
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] |
9379 | A sentence is obvious if it is true, and any speaker of the language will instantly agree to it [Quine] |