Journal of the History of Philosophy

334 HISTORY OF PHILOSOPHY UNKNOWN FACULTIES AND DESCARTES'S FIRST PROOF OF THE EXISTENCE OF GOD In reply to David Fate Norton's paper "Descartes on Unknown Faculties: An Essential Inconsistency,"1 Leonard E. Brewster gives a clever argument to show that the possibility that Descartes has an unknown faculty supports Descartes's first proof for the existence of God. 2 Norton, in response to Brewster, points out a flaw in Brewster's argument. 3 I wish to show that although Brewster's argument is invalid as stated, it can be revised to prove his original conclusion. In the paper that spawned this controversy, Norton argues that Descartes's admission in Meditation 3 that he may have an unknown faculty undermines Descartes's first proof of the existence of God. 4 For if Descartes may have, unknown to himself, a faculty capable of producing any idea, s he cannot know that his idea of God was not produced by himself and hence cannot infer from the existence of this idea to the existence of God. 6 Brewster, in reply to Norton, argues that the possibility of an unknown faculty does not invalidate Descartes's first proof of the existence of God but, on the contrary, supports it. 7 He argues that if Descartes does possess an unknown faculty or does not know whether he has one, it would follow that there is something that Descartes does not know and hence that he is not omniscient. But then, given Descartes's causal principle "qu'il doit y auoir pour le moins autant de realit6 dans la cause efficiente & totale que dans son effect ''s and that Descartes has an idea of God as omniscient, it follows, says Brewter, that Descartes's idea of God "cannot originate in him, but must come from something outside of him, and this can only be God. ''9 While admitting the ingeniousness of Brewster's argument, Norton objects that it is "clearly question-begging."1~ He explains: The issue to be dealt with is not the narrow one of Descartes' omniscience, but the broader one of his powers. Descartes must (to avoid inconsistency) prove that he has not the power to produce the idea of God, which is, admittedly, an idea of a being of great perfection. This might be a simple enough task had he not suggested that he could have a hidden faculty which is the source of this idea. But he did make this proposal, and hence he must demonstrate, not that he is ' Journal of the History of Philosophy 6 (July 1968):245-256. 2"How to Know Enough About the Unknown Faculty," Journal of the History of Philosophy 12 (July 1974):366-371. "Descartes' Inconsistency: A Reply," Journal of the History of Philosophy 12(October 1974):509-520. 4 Oeuvres de Descartes, ed. Charles Adam and Paul Tannery, 13 vols. (Paris: Libraire Philosophique J. Vrin, 1964-1974), 9, pt. 1:31; hereafter cited as AT. The Philosophical Works of Descartes, trans. Elizabeth S. Haldane and G. R. T. Ross, 2 vols. (Cambridge: Cambridge University Press, 1968), 1:161; hereafter cited as HR. s Norton takes Descartes's statement that, "peut-estre qu'il y a en moy quelque facult6 ou puissance propre Aproduire ces id6essans l'ayded'aucunes choses exterieures, bien qu'ellene me soit pas encore connu~," (AT 9, pt. ! :31) to imply that perhaps Descartes has an unknown faculty capable of producing any idea ("Unknown Faculties," p. 245). Ted B. Humphrey has criticized Norton for this, and 1 think justly so ("How Descartes Avoids the Hidden Faculties Trap," Journal of the History of Philosophy 12 [July 1974]:371-377). But see Norton's reply to Humphrey ("Descartes' Inconsistency," pp. 515-517). Norton, "Unknown Faculties," pp. 249-250. 7Brewster, p. 367. SAT9, pt. 1:32; see also HR I:162. 9 Brewster, p. 367. 1o"Descartes' Inconsistency," p. 511. NOTES AND DISCUSSIONS 335 not omniscient, but that he has not, formally or eminently, the perfection required to produce the objective reality represented by the idea of omniscience and the idea of God. The fact that Descartes says that he could have an unknown faculty may well show that he is...