Combining Texts

All the ideas for 'Aristotle and Descartes on Matter', 'Reference and Essence: seven appendices' and 'Introduction to Russell's Theory of Types'

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4 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
18170 The Axiom of Reducibility is self-effacing: if true, it isn't needed [Quine]
     Full Idea: The Axiom of Reducibility is self-effacing: if it is true, the ramification it is meant to cope with was pointless to begin with.
     From: Willard Quine (Introduction to Russell's Theory of Types [1967], p.152), quoted by Penelope Maddy - Naturalism in Mathematics I.1
     A reaction: Maddy says the rejection of Reducibility collapsed the ramified theory of types into the simple theory.
7. Existence / D. Theories of Reality / 10. Vagueness / g. Degrees of vagueness
14742 It can't be indeterminate whether x and y are identical; if x,y is indeterminate, then it isn't x,x [Salmon,N]
     Full Idea: Insofar as identity seems vague, it is provably mistaken. If it is vague whether x and y are identical (as in the Ship of Theseus), then x,y is definitely not the same as x,x, since the first pair is indeterminate and the second pair isn't.
     From: Nathan Salmon (Reference and Essence: seven appendices [2005], App I)
     A reaction: [compressed; Gareth Evans 1978 made a similar point] This strikes me as begging the question in the Ship case, since we are shoehorning the new ship into either the slot for x or the slot for y, but that was what we couldn’t decide. No rough identity?
19. Language / B. Reference / 3. Direct Reference / a. Direct reference
18885 Kripke and Putnam made false claims that direct reference implies essentialism [Salmon,N]
     Full Idea: Kripke and Putnam made unsubstantiated claims, indeed false claims, to the effect that the theory of direct reference has nontrivial essentialist import.
     From: Nathan Salmon (Reference and Essence: seven appendices [2005], Pref to Exp Ed)
     A reaction: Kripke made very few claims, and is probably innocent of the charge. Most people agree with Salmon that you can't derive metaphysics from a theory of reference.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
19399 Prime matter is nothing when it is at rest [Leibniz]
     Full Idea: Primary matter is nothing if considered at rest.
     From: Gottfried Leibniz (Aristotle and Descartes on Matter [1671], p.90)
     A reaction: This goes with Leibniz's Idea 13393, that activity is the hallmark of existence. No one seems to have been able to make good sense of prime matter, and it plays little role in Aristotle's writings.