Demea's a priori Theistic Proof

Hume Studies Volume 29, Number 1, April 2003, pp. 99-123 Demea's a priori Theistic Proof KENNETH WILLIFORD I. Introductory Hume's examination of the causal maxim in 1.3.3 of A Treatise of Human Nature (hereafter T) can be considered, at least in part, a thinly veiled critique of the cosmological argument, attacking as it does the privileged status of the principle upon which that proof rests (see T 1.3.3.1-9; SBN 78-82).: As well, Hume's remarks on the impossibility of demonstrating matters of fact a priori in part 3 of section 12 oÃ- An Enquiry concerning Human Understanding (hereafter EHU) clearly strike at the heart of the ontological argument, even if not explicitly (see EHU 12.24-34; SBN 161-5).2 Unfortunately, it is only in the very brief part 9 of his Dialogues Concerning Natural Religion (hereafter DNR) that Hume directly discusses, at any length, the attempt to demonstrate a priori the existence of a deity (see DNR 9.1-11; 188-92).3 The argument, put forward by Demea, and Cleanthes's criticism of that argument take up so little space that for ease of reference I will reproduce them before we proceed any further. Part 9 consists of eleven paragraphs, and in accordance with a now fairly common convention, I will refer to the paragraphs by number.41 reproduce only those paragraphs that will be the focus of this paper. Demea's Argument (DNR 9.3; 188-9): [3] The argument, replied DEMEA, which I would insist on is the common one. Whatever exists must have a cause or reason of its Kenneth Williford is Visiting Assistant Professor of Philosophy at the University of Iowa, 269 EPB, Iowa City, IA 52242, USA. e-mail: kenneth-williford@uiowa.edu 100 Kenneth Williford existence; it being absolutely impossible for any thing to produce itself, or be the cause of its own existence. In mounting up, therefore , from effects to causes, we must either go on in tracing an infinite succession, without any ultimate cause at all, or must at last have recourse to some ultimate cause, that is necessarily existent : Now that the first supposition is absurd may be thus proved. In the infinite chain or succession of causes and effects, each single effect is determined to exist by the power and efficacy of that cause which immediately preceded; but the whole eternal chain or succession , taken together, is not determined or caused by any thing: And yet it is evident that it requires a cause or reason, as much as any particular object, which begins to exist in time. The question is still reasonable, why this particular succession of causes existed from eternity, and not any other succession, or no succession at all. If there be no necessarily existent Being, any supposition, which can be formed, is equally possible; nor is there any more absurdity in nothing's having existed from eternity, than there is in that succession of causes, which constitutes the universe. What was it, then, which determined something to exist rather than nothing, and bestowed being on a particular possibility, exclusive of the rest? External causes, there are supposed to be none. Chance is a word without meaning. Was it nothing? But that can never produce anything . We must, therefore, have recourse to a necessarily existent Being, who carries the REASON of his existence in himself; and who cannot be supposed not to exist without an express contradiction. There is consequently such a Being, that is, there is a Deity. Cleanthes's Core Response (DNR 9.5-6; 189-90): [5] I shall begin with observing, that there is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by any arguments a priori. Nothing is demonstrable, unless the contrary implies a contradiction. Nothing, that is distinctly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no Being, therefore, whose nonexistence implies a contradiction. Consequently there is no Being, whose existence is demonstrable. I propose this argument as entirely decisive, and am willing to rest the whole controversy upon it. Hume...