12 ideas
16456 | For modality Lewis rejected boxes and diamonds, preferring worlds, and an index for the actual one [Lewis, by Stalnaker] |
Full Idea: Lewis was suspicious of boxes and diamonds as regimenting ordinary modal thought, …preferring a first-order extensional theory including possible worlds in its domain and an indexical singular term for the actual world. | |
From: report of David Lewis (Anselm and Actuality [1970]) by Robert C. Stalnaker - Mere Possibilities 3.8 |
13437 | A CAR and its major PART can become identical, yet seem to have different properties [Gallois] |
Full Idea: At t1 there is a whole CAR, and a PART of it, which is everything except the right front wheel. At t2 the wheel is removed, leaving just PART, so that CAR is now PART. But PART was a proper part of CAR, and CAR had the front wheel. Different properties! | |
From: André Gallois (Occasions of Identity [1998], 1.II) | |
A reaction: [compressed summary] The problem is generated by appealing to Leibniz's Law. My immediate reaction is that this is the sort of trouble you get into if you include such temporal truths about things as 'properties'. |
11976 | Aristotelian essentialism says essences are not relative to specification [Lewis] |
Full Idea: So-called 'Aristotelian essentialism' is the doctrine of essences not relative to specifications. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], III) | |
A reaction: In other words, they are so-called 'real essences', understood as de re. Quine says essences are all de dicto, and relative to some specification. I vote for Aristotle. |
16233 | Gallois hoped to clarify identity through time, but seems to make talk of it impossible [Hawley on Gallois] |
Full Idea: A problem for Gallois is that he leaves us no way to talk about questions of genuine identity through time, and thus undercuts one motivation for his own position. | |
From: comment on André Gallois (Occasions of Identity [1998]) by Katherine Hawley - How Things Persist 5.8 | |
A reaction: Gallois seems to need a second theory of identity to support his Occasional Identity theory. Two things need an identity each, before we can say that the two identities coincide. (Time to read Gallois!) |
14755 | Gallois is committed to identity with respect to times, and denial of simple identity [Gallois, by Sider] |
Full Idea: Gallois's core claim is that the identity relation holds with respect to times, ...and he must claim that there is no such thing as the relation of identity simpliciter. | |
From: report of André Gallois (Occasions of Identity [1998]) by Theodore Sider - Four Dimensionalism 5.5 | |
A reaction: Gallois is essentially responding to the statue and clay problem, but it seems a bit drastic to entirely change our concept of two things being identical, such as Hesperus and Phosphorus. 'Identity' seems to have several meanings; let's sort them out. |
16231 | Occasional Identity: two objects can be identical at one time, and different at others [Gallois, by Hawley] |
Full Idea: Gallois' Occasional Identity Thesis is that objects can be identical at one time without being identical at all times. | |
From: report of André Gallois (Occasions of Identity [1998]) by Katherine Hawley - How Things Persist 5.4 | |
A reaction: The analogy is presumably with two crossing roads being identical at one place but not at others. It is a major misunderstanding to infer from Special Relativity that time is just like space. |
11978 | Causal necessities hold in all worlds compatible with the laws of nature [Lewis] |
Full Idea: Just as a sentence is necessary if it holds in all worlds, so it is causally necessary if it holds in all worlds compatible with the laws of nature. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], V) | |
A reaction: I don't believe in the so-called 'laws of nature', so I'm not buying that. Is there no distinction in Lewis's view between those sentences which must hold, and those which happen to hold universally? |
11979 | It doesn't take the whole of a possible Humphrey to win the election [Lewis] |
Full Idea: Even if Humphrey is a modal continuant, it doesn't take the whole of him to do such things as winning. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], Post B) | |
A reaction: This responds to Kripke's famous example, that people only care about what happens to themselves, and not to some 'counterpart' of themselves. |
16994 | Counterpart theory is bizarre, as no one cares what happens to a mere counterpart [Kripke on Lewis] |
Full Idea: Probably Humphrey could not care less whether someone else, no matter how much resembling him, would have been victorious in another possible world. Thus Lewis's view seems even more bizarre that the usual transworld identification it replaces. | |
From: comment on David Lewis (Counterpart theory and Quant. Modal Logic [1968]) by Saul A. Kripke - Naming and Necessity notes and addenda note 13 | |
A reaction: I begin to see this as a devastating reply to a theory I previously found quite congenial. |
11974 | Counterparts are not the original thing, but resemble it more than other things do [Lewis] |
Full Idea: Your counterparts resemble you closely in content and context in important respects. They resemble you more closely than do the other things in their worlds. But they are not really you. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], I) | |
A reaction: It is a dilemma. If my counterpart were exactly me, I couldn't contemplate possibly losing a leg, or my sanity. But if my counterpart isn't exactly me, then I don't have much interest in its fate. Only essences can save us here. Cf. me tomorrow. |
11975 | If the closest resembler to you is in fact quite unlike you, then you have no counterpart [Lewis] |
Full Idea: If whatever thing in world w6 it is that resembles you more closely than anything else in w6 is nevertheless quite unlike you; nothing in w6 resembles you at all closely. If so, you have no counterpart in w6. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], I) | |
A reaction: This is the nub, because the whole theory rests on deciding whether two things resemble sufficiently 'closely'. But then we need a criterion of closeness, so we must start talking about which properties matter. Essences loom. |
11977 | Essential attributes are those shared with all the counterparts [Lewis] |
Full Idea: An essential attribute of something is an attribute it shares with all its counterparts. | |
From: David Lewis (Counterpart theory and Quant. Modal Logic [1968], III) | |
A reaction: I don't like this. It ties essence entirely to identity, but I think essence precedes identity. Essence is a nexus of causal and explanatory powers which bestows an identity on each thing. But essence might be unstable, and identity with it. |