3 ideas
18244 | I say the irrational is not the cut itself, but a new creation which corresponds to the cut [Dedekind] |
Full Idea: Of my theory of irrationals you say that the irrational number is nothing else than the cut itself, whereas I prefer to create something new (different from the cut), which corresponds to the cut. We have the right to claim such a creative power. | |
From: Richard Dedekind (Letter to Weber [1888], 1888 Jan), quoted by Stewart Shapiro - Philosophy of Mathematics 5.4 | |
A reaction: Clearly a cut will not locate a unique irrational number, so something more needs to be done. Shapiro remarks here that for Dedekind numbers are objects. |
19216 | Propositions (such as 'that dog is barking') only exist if their items exist [Williamson] |
Full Idea: A proposition about an item exists only if that item exists... how could something be the proposition that that dog is barking in circumstances in which that dog does not exist? | |
From: Timothy Williamson (Necessary Existents [2002], p.240), quoted by Trenton Merricks - Propositions | |
A reaction: This is a view of propositions I can't make sense of. If I'm under an illusion that there is a dog barking nearby, when there isn't one, can I not say 'that dog is barking'? If I haven't expressed a proposition, what have I done? |
3032 | I can form no notion of what the good is [Amphis] |
Full Idea: What the good is I no more can form a notion of, than of the good of Plato. | |
From: Amphis (comedies (frags) [c.350 BCE]), quoted by Diogenes Laertius - Lives of Eminent Philosophers 03.1.22 | |
A reaction: It was evidently a running joke in the ancient world that no one could define Plato's Form of the Good. He was said to have written a book on it, now lost. |