2 ideas
8972 | What in the real world could ground the distinction between the sets {A,{A,B}} and {B,{A,B}}? [Inwagen] |
Full Idea: Nothing in the world of nominalistically acceptable things could ground or explain the non-identity of the set {A,{A,B}} with the set {B,{A,B}}. | |
From: Peter van Inwagen (Existence,Ontological Commitment and Fictions [2003], p.154) | |
A reaction: [He cites Goodman for this thought] Van Inwagen is offering this to show that the existence of sets is abstract, whereas Goodman was denying the existence of sets altogether. I'm with Goodman. Nice example. |
12812 | Things have real essences, but we categorise them according to the ideas we receive [Locke] |
Full Idea: This I do say, that there are real constitutions in things from whence simple ideas flow, which we observe combin'd in them. But we distinguish particular substances into sorts or genera not by real essences or constitutions, but by observed simple ideas. | |
From: John Locke (Letters to William Molyneux [1692], 1693.01.20) | |
A reaction: This is the clearest statement I can find of Locke's position on essences. He is totally committed to their reality, but strongly aware of the empirical constraints which keep us from direct knowledge of them. He would be amazed by modern discoveries. |