Combining Philosophers

Ideas for Roger Penrose, Michael Bratman and Peter Simons

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4 ideas

9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
A whole requires some unique relation which binds together all of the parts [Simons]
     Full Idea: A whole must at least approximate to this condition: every member of some division of the object stands in a certain relation to every other member, and no member bears this relation to anything other than members of the division.
     From: Peter Simons (Parts [1987], 9.2)
     A reaction: Simons proceeds to formalise this, and I suspect that he goes for this definition because (unlike looser ones) it can be formalised. See Simons's Idea 12865. We'll need to know whether these are internal or external relations.
9. Objects / B. Unity of Objects / 3. Unity Problems / b. Cat and its tail
Tibbles isn't Tib-plus-tail, because Tibbles can survive its loss, but the sum can't [Simons]
     Full Idea: There mere fact that Tibbles can survive the mutilation of losing a tail, whereas the sum of Tib and the tail cannot, is enough to distinguish them, even if no such mutilation ever occurs.
     From: Peter Simons (Parts [1987], 6.1)
     A reaction: See Idea 12835 for details of the Tibbles example. Either we go for essentialism here, or the whole notion of identity collapses. But the essential features of a person are not just those whose loss would kill them.
Does Tibbles remain the same cat when it loses its tail? [Simons]
     Full Idea: The cat is 'Tibbles' with a tail; 'Tib' is Tibbles after the loss of the tail. 1) Tibbles isn't Tib at t; 2) Tibbles is Tib at t'; 3) Tibbles at t is Tibbles at t'; 4) Tib at t is Tib at t'; so 5) Tibbles at t is Tib at t (contradicting 1). What's wrong?
     From: Peter Simons (Parts [1987], 3.3)
     A reaction: [The example is in Wiggins 1979, from Geach, from William of Sherwood] Simons catalogues nine assumptions which are being made to produce the contradiction. 1) rests on Leibniz's law. Simons says two objects are occupying Tibbles.
9. Objects / B. Unity of Objects / 3. Unity Problems / d. Coincident objects
Without extensional mereology two objects can occupy the same position [Simons]
     Full Idea: If we reject extensionality in mereology, it has as a consequence that more than one object may have exactly the same parts at the same time, and hence occupy the same position.
     From: Peter Simons (Parts [1987], Intro)
     A reaction: Simons defends this claim. I'm unconvinced that we must choose between the two views. The same parts should ensure the same physical essence, which seems to guarantee the same identity. Not any old parts generate an essence.