1 Frege, G., The Foundations of Arithmetic, translated by Austin, J. L. (Oxford: Basil Blackwell, 1974), p. 36.Google Scholar

2 Collins, Arthur, The Nature of Mental Things (Notre Dame, IN: University of Notre Dame Press, 1987), chap. 2.Google Scholar

3 I hedge here largely because of Arthur Collins's account of Kant in Possible Experience: Understanding Kant's Critique of Pure Reason (Berkeley, CA: University of California Press, 1999).Google Scholar

4 Kant further holds, evidently, that a proof of an object's “permanence” is a proof of its outerness. Taken together with a proof of the directness of our perception of objects, this makes a proof of the external world and, apropos the scandal to philosophy that Kant laments, he can declare that our long international nightmare is over. See Kant's, Critique of Pure Reason, translated and edited by Guyer, Paul and Wood, Allen W. (New York: Cambridge University Press, 1998), pp. 121–22, 326–29.CrossRefGoogle Scholar

5 Similarly, it is an analytic truth that primeness is a number property. Its misascription to a number must be distinguished from the conceptual fiasco which would be its misascription to a lemon. The misascription of primeness to a lemon would just be muddle, as Descartes insisted the ascription of yellow to a lemon is. But Descartes needs to look at the man in the mirror.

6 Wittgenstein, L., Philosophical Investigations (Oxford: Basil Blackwell, 1953), sec. 381.Google Scholar

7 A proof of the externality of colour is ipso facto a proof of the external world, the lack of which Kant deplored. But such a reassuring result does not depend on reference to colour. The same sort of argument as above can be made for “bodies” (i.e., “Newtonian bodies,” “res extensa”) or an external world tout compris: (1) Bodies are outer things (analytic); (2) We directly perceive bodies (direct realism); therefore, (3) Outer things exist. QED. A too-easy victory? It certainly should be. One could also argue, either concerning colour or an external world entire, that insofar as Hume is wrong that our sight informs us not of outness and Merleau-Ponty is right that to see is to see in depth, the reality of perception entails the reality of an external world. In order to see anything, it must be located some distance from the perceiver (who thus must also be in the external world) if only—though not only only—to let in some light, which also must be extended and external, though not a body. (I don't take seriously the suggestion that imagination, dreams, or even hallucinations are intrinsically indistinguishable from normal lsqb;drug-free and well-rested!] perception.) The point in any of these arguments is not, of course, to convince anyone that (phew!) there is an external world, but to convince that these are proofs (or “proofs”) of such. So too with proofs (or “proofs”) of “other minds.”

8 Bouwsma, O. K., “Descartes' Evil Genius,” in his Philosophical Essays (Lincoln, NE: University of Nebraska Press, 1965).Google Scholar