11 ideas
| 14212 | A consistent theory just needs one model; isomorphic versions will do too, and large domains provide those [Lewis] |
| Full Idea: A consistent theory is, by definition, one satisfied by some model; an isomorphic image of a model satisfies the same theories as the original model; to provide the making of an isomorphic image of any given model, a domain need only be large enough. | |
| From: David Lewis (Putnam's Paradox [1984], 'Why Model') | |
| A reaction: This is laying out the ground for Putnam's model theory argument in favour of anti-realism. If you are chasing the one true model of reality, then formal model theory doesn't seem to offer much encouragement. |
| 14213 | Anti-realists see the world as imaginary, or lacking joints, or beyond reference, or beyond truth [Lewis] |
| Full Idea: Anti-realists say the only world is imaginary, or only has the parts or classes or relations we divide it into, or doubt that reference to the world is possible, or doubt that our interpretations can achieve truth. | |
| From: David Lewis (Putnam's Paradox [1984], 'Why Anti-R') | |
| A reaction: [compression of a paragraph on anti-realism] Lewis is a thoroughgoing realist. A nice example of the rhetorical device of ridiculing an opponent by suggesting that they don't even know what they themselves believe. |
| 18439 | Because things can share attributes, we cannot individuate attributes clearly [Quine] |
| Full Idea: No two classes have exactly the same members, but two different attributes may be attributes of exactly the same things. Classes are identical when their members are identical. ...On the other hand, attributes have no clear principle of individuation. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.100) |
| 18442 | You only know an attribute if you know what things have it [Quine] |
| Full Idea: May we not say that you know an attribute only insofar as you know what things have it? | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.106) | |
| A reaction: Simple, and the best defence of class nominalism (a very implausible theory) which I have encountered. Do I have to know all the things? Do I not know 'red' if I don't know tomatoes have it? |
| 18441 | No entity without identity (which requires a principle of individuation) [Quine] |
| Full Idea: We have an acceptable notion of class, or physical object, or attribute, or any other sort of object, only insofar as we have an acceptable principle of individuation for that sort of object. There is no entity without identity. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.102) | |
| A reaction: Note that this is his criterion for an 'acceptable' notion. Presumably that is for science. It permits less acceptable notions which don't come up to the standard. And presumably true things can be said about the less acceptable entities. |
| 14082 | No sortal could ever exactly pin down which set of particles count as this 'cup' [Schaffer,J] |
| Full Idea: Many decent candidates could the referent of this 'cup', differing over whether outlying particles are parts. No further sortal I could invoke will be selective enough to rule out all but one referent for it. | |
| From: Jonathan Schaffer (Deflationary Metaontology of Thomasson [2009], 3.1 n8) | |
| A reaction: I never had much faith in sortals for establishing individual identity, so this point comes as no surprise. The implication is strongly realist - that the cup has an identity which is permanently beyond our capacity to specify it. |
| 14210 | A gerrymandered mereological sum can be a mess, but still have natural joints [Lewis] |
| Full Idea: The mereological sum of the coffee in my cup, the ink in this sentence, a nearby sparrow, and my left shoe is a miscellaneous mess of an object, yet its boundaries are by no means unrelated to the joints of nature. | |
| From: David Lewis (Putnam's Paradox [1984], 'What Might') | |
| A reaction: In that case they do, but if there are no atoms at the root of physics then presumably their could also be thoroughly jointless assemblages, involving probability distributions etc. Even random scattered atoms seem rather short of joints. |
| 18440 | Identity of physical objects is just being coextensive [Quine] |
| Full Idea: Physical objects are identical if and only if coextensive. | |
| From: Willard Quine (On the Individuation of Attributes [1975], p.101) | |
| A reaction: The supposed counterexample to this is the statue and the clay it is made of, which are said to have different modal properties (destroying the statue doesn't destroy the clay). |
| 14081 | Identities can be true despite indeterminate reference, if true under all interpretations [Schaffer,J] |
| Full Idea: There can be determinately true identity claims despite indeterminate reference of the terms flanking the identity sign; these will be identity claims true under all admissible interpretations of the flanking terms. | |
| From: Jonathan Schaffer (Deflationary Metaontology of Thomasson [2009], 3.1) | |
| A reaction: In informal contexts there might be problems with the notion of what is 'admissible'. Is 'my least favourite physical object' admissible? |
| 14215 | Causal theories of reference make errors in reference easy [Lewis] |
| Full Idea: Whatever happens in special cases, causal theories usually make it easy to be wrong about the thing we refer to. | |
| From: David Lewis (Putnam's Paradox [1984], 'What Is') | |
| A reaction: I suppose the point of this is that there are no checks and balances to keep reference in focus, but just a requirement to keep connected to an increasingly attenuated causal chain. |
| 14209 | Descriptive theories remain part of the theory of reference (with seven mild modifications) [Lewis] |
| Full Idea: Description theories of reference are supposed to have been well and truly refuted. I think not: ..it is still tenable with my seven points, and part of the truth of reference [7: rigidity, egocentric, tokens, causal, imperfect, indeterminate, families]. | |
| From: David Lewis (Putnam's Paradox [1984], 'Glob Desc') | |
| A reaction: (The bit at the end refers to his seven points, on p.59). He calls his basic proposal 'causal descriptivism', incorporating his seven slight modifications of traditional descriptivism about reference. |