display all the ideas for this combination of texts
10 ideas
| 11843 | Identity over a time and at a time aren't different concepts [Wiggins] |
| Full Idea: People often speak of identity over time and distinguish it from identity at a time. But identity is just identity. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.3) | |
| A reaction: I myself am guilty of such usage, but it doesn't imply a commitment to a multivocal concept. The epistemological issues (of explaining what it is now, and simply reidentifying it later) seem profoundly different. Hume only admits identity over time. |
| 11864 | Hesperus=Hesperus, and Phosphorus=Hesperus, so necessarily Phosphorus=Hesperus [Wiggins] |
| Full Idea: The simple proof (from Ruth Barcan Marcus) is: Hesperus is necessarily Hesperus, so if Phosphorus is Hesperus, then Phosphorus is necessarily Hesperus. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 4.3) | |
| A reaction: This is the famous idea which she noticed well before Kripke. The point is that the simple logic of the case bestows a necessity on the identity. We shouldn't be confused by the a posteriori and contingent nature of the discovery. |
| 11831 | The formal properties of identity are reflexivity and Leibniz's Law [Wiggins] |
| Full Idea: The formal properties of identity are the reflexivity of identity, and Leibniz's Law (if x is the same as y, then whatever is true of one is true of the other). | |
| From: David Wiggins (Sameness and Substance Renewed [2001], Pr.2) | |
| A reaction: Presumably transitivity will also apply, and, indeed, symmetry. He seems to mean something like the 'axiomatic formal properties'. |
| 16795 | Same person, man or substance are different identities, belonging to different ideas [Locke] |
| Full Idea: It is one thing to be the same substance, another the same man, and a third the same person, if Person, Man and Substance are three names standing for three different ideas; for such as is the idea belonging to the name, such must be the identity. | |
| From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.27.07) | |
| A reaction: It might be better to say that two things can only be 'the same' in some respect. You can say 'in some respects they are the same', without citing the respects. |
| 14362 | Relative Identity is incompatible with the Indiscernibility of Identicals [Wiggins, by Strawson,P] |
| Full Idea: Wiggins argues that Geach's Relative Identity is incompatible with the formal properties of identity, which include, besides transitivity, symmetry and reflexivity, the complete community of properties defined by the Indiscernibility of Identicals. | |
| From: report of David Wiggins (Sameness and Substance Renewed [2001]) by Peter F. Strawson - Review of 'Sameness and Substance' p.603 | |
| A reaction: The tricky part is that Wiggins then goes on to say that identity depends on sortals, which sounds very close to the Geach view. I find disentangling them tricky. See Idea 14363 for a helpful comment from Strawson. |
| 11838 | Relativity of Identity makes identity entirely depend on a category [Wiggins] |
| Full Idea: The thesis of Relativity of Identity (which I steadfastly oppose) ..suggests that it makes all the difference to keeping track of continuants through space and time which concept one subsumes something under. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 1.1) | |
| A reaction: [Geach I take to be the villain of this idea] The point is that identity is entirely relative to the sortal concept, where Wiggins wants to make identity a combination of the object itself and our concept of it (I think). |
| 11847 | To identify two items, we must have a common sort for them [Wiggins] |
| Full Idea: As a necessary condition of the truth of an identity claim, some common sort f will have to be found to which they each belong. That is the point at which the primary question of identity can come into focus. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.2) | |
| A reaction: This is the plainest English expression I can find of Wiggins's main thesis. He maintains this thesis, while adamantly denying the idea that identity consists entirely of falling under a concept. |
| 12504 | Two things can't occupy one place and time, which leads us to the idea of self-identity [Locke] |
| Full Idea: We don't conceive it possible that two things of the same kind should exist in the same place and time...When, therefore, we demand whether any thing be the same or no, it refers to something that existed at a time and place, and was the same with itself. | |
| From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.27.01) | |
| A reaction: I find the notion of 'self-identity' puzzling. I've always taken it to be a logicians' idea, but Locke seems to arrive at it by looking for whatever is identical with some original object, and the floating relation having to hook back onto itself. |
| 11839 | Do both 'same f as' and '=' support Leibniz's Law? [Wiggins] |
| Full Idea: Is Leibniz's Law as true for 'is the same as' as it is for '='? | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 1.2) | |
| A reaction: [By Leibniz's Law he means if they are the same, they support the same truths] |
| 11845 | Substitutivity, and hence most reasoning, needs Leibniz's Law [Wiggins] |
| Full Idea: Leibniz's Law underwrites the substitutivity of identity and this is a principle not long dispensable in any form of reasoning. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.7) | |
| A reaction: Thus the modern fashion of deriving our metaphysics from our logic. Presumably we can derive it from our epistemology too, or even from our intuitions, if we thought they were good enough as evidence. |