9 ideas
15034 | Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry] |
Full Idea: I shall beg off talking of a) whether genera and species are real or situated in bare thoughts alone, b) whether as real they are bodies or incorporeals, and c) whether they are separated or in sensibles and have their reality in connection with them. | |
From: Porphyry (Isagoge ('Introduction') [c.295], (2)) | |
A reaction: This passage, picking up on Aristotle, seems to be the original source that grew into the medievel debate about universals. It seems to rather neatly lay out the agenda for the universals debate which is still with us. |
11984 | Asserting a possible property is to say it would have had the property if that world had been actual [Plantinga] |
Full Idea: To say than x has a property in a possible world is simply to say that x would have had the property if that world had been actual. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
A reaction: Plantinga tries to defuse all the problems with identity across possible worlds, by hanging on to subjunctive verbs and modal modifiers. The point, though, was to explain these, or at least to try to give their logical form. |
11980 | A possible world is a maximal possible state of affairs [Plantinga] |
Full Idea: A possible world is just a maximal possible state of affairs. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
A reaction: The key point here is that Plantinga includes the word 'possible' in his definition. Possibility defines the worlds, and so worlds cannot be used on their own to define possibility. |
11982 | If possible Socrates differs from actual Socrates, the Indiscernibility of Identicals says they are different [Plantinga] |
Full Idea: If the Socrates of the actual world has snubnosedness but Socrates-in-W does not, this is surely inconsistent with the Indiscernibility of Identicals, a principle than which none sounder can be conceived. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
A reaction: However, we allow Socrates to differ over time while remaining the same Socrates, so some similar approach should apply here. In both cases we need some notion of what is essential to Socrates. But what unites aged 3 with aged 70? |
11983 | It doesn't matter that we can't identify the possible Socrates; we can't identify adults from baby photos [Plantinga] |
Full Idea: We may say it makes no sense to say that Socrates exists at a world, if there is in principle no way of identifying him. ...But this is confused. To suppose Agnew was a precocious baby, we needn't be able to pick him from a gallery of babies. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], I) | |
A reaction: This seems a good point, and yet we have a space-time line joining adult Agnew with baby Agnew, and no such causal link is available between persons in different possible worlds. What would be the criterion in each case? |
11985 | If individuals can only exist in one world, then they can never lack any of their properties [Plantinga] |
Full Idea: The Theory of Worldbound Individuals contends that no object exists in more than one possible world; this implies the outrageous view that - taking properties in the broadest sense - no object could have lacked any property that it in fact has. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
A reaction: Leibniz is the best known exponent of this 'outrageous view', though Plantinga shows that Lewis may be seen in the same light, since only counterparts are found in possible worlds, not the real thing. The Theory does seem wrong. |
11986 | The counterparts of Socrates have self-identity, but only the actual Socrates has identity-with-Socrates [Plantinga] |
Full Idea: While Socrates has no counterparts that lack self-identity, he does have counterparts that lack identity-with-Socrates. He alone has that - the property, that is, of being identical with the object that in fact instantiates Socrateity. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
A reaction: I am never persuaded by arguments which rest on such dubious pseudo-properties. Whether or not a counterpart of Socrates has any sort of identity with Socrates cannot be prejudged, as it would beg the question. |
11987 | Counterpart Theory absurdly says I would be someone else if things went differently [Plantinga] |
Full Idea: It makes no sense to say I could have been someone else, yet Counterpart Theory implies not merely that I could have been distinct from myself, but that I would have been distinct from myself had things gone differently in even the most miniscule detail. | |
From: Alvin Plantinga (Transworld Identity or worldbound Individuals? [1973], II) | |
A reaction: A counterpart doesn't appear to be 'me being distinct from myself'. We have to combine counterparts over possible worlds with perdurance over time. I am a 'worm' of time-slices. Anything not in that worm is not strictly me. |
15314 | Faraday's single field of variable forces introduces a criterion of Unity into what is ultimate [Faraday, by Harré/Madden] |
Full Idea: In Faraday lines of force picture the directional structure of powers,...so the fundamental entity is a single, unified field. ...A new criterion of the ultimate has stepped in: Unity. The universal field is still the final explanation, but not invariant. | |
From: report of Michael Faraday (Experimental Researches in Electricity [1859]) by Harré,R./Madden,E.H. - Causal Powers 9.II.B | |
A reaction: Almost Parmenides, except that the field is not invariant. But that was always the ancient objection to the One - that it offered no explanation of change. |