Giving a Good Account of God: Is Theology Ever Mathematical?

The Thomist 70 (2006): 367-93 GIVING A GOOD ACCOUNT OF GOD: IS THEOLOGY EVER MATHEMATICAL?1 LAURENCE PAUL HEMMING Heythrop College, University ofLondon London, England OME YEARS AGO I examined a thesis for the Catholic University of Leuven written purporting to offer a definitive mathematical proof for the reality and necessity of the Divine Trinity. At its heart lay an equation, which-it was argued-if factored on both sides, produced the result that three is equal to one. On first acquaintance I was impressed, if a little baffled, until I took myself again through the steps of the proof (enlisting the help of a banker, someone for whom mathematics really counts). Offering only the reason (quite correctly) that factors may be used to simplify equations, my candidate had divided by a factor of three on one side of his equation and nine on the other. The numerically agile will know that this indeed yields the result that three is equal to one. The candidate had neglected to ensure that the same factor was used on each side of the equation to which factors are applied: the thesis, mathematically at least, was false. Nevertheless the underlying instinct for this student's argument stands in a tradition that stretches back at least as far as Descartes, if not all the way to Plato and the Pythagoreans: that the mathematical may inform the theological, and even be used to demonstrate (or in Descartes's case, prove) certain kinds of theological truth. What is at issue here is the relationship between 1 A version of this paper was given at the Cambridge 'D' Society on 10 March 2006, by kind invitation of Dr. Douglas Hedley and Dr. Chris Insole of the Cambridge University Divinity Faculty. 367 368 LAURENCE PAUL HEMMING philosophy and theology-taking the commonly understood view of mathematics as a form of rational thinking, von Leibniz's claim that logic is mathesis genera/is. The philosophical and theological are thereby inherently united; they can be made to treat of the same things in the same way. Notwithstanding a vigorous polemic against this view from at least as far back as Luther up to Karl Barth and beyond, the possibility of this connection is retraced by Denys Turner in the central contention (I hesitate to say argument, since the very premise of the book is that none need be supplied) of his Faith, Reason, and the Existence ofGod, that "the existence of God is rationally demonstrable."2 In fact many contemporary theologians, especially those declaring themselves to be among the most orthodox, make little or no distinction between philosophy and theology (theo-ontologies abound). There is a presumption that the existence, being, or essence, of God can, by means mathematical, logical, or analogical, be bound to the being of being human. This connection is negative: we remain orthodox provided we say nothing of the 'whatness' (quidditas) of the divine essence, only that it is, or that an argument can be had by which means it could thereby be said 'to be' (which I take be the essence of Turner's argument absconditus). I want to examine this claim by appealing to Martin Heidegger's critique of the relation between mathematics and theology, especially in relation to Descartes, in notes he made between 1938 and 1939-especially in relation to his reading of Nietzsche, and made available in his Collected Works only in 1999. Heidegger makes a series of astonishing polemical remarks about the relation of theology and mathematics. He begins by speaking of the age of the "theologies," which is at the same time the age of the "end of all metaphysics"; he means by this our 2 D. Turner, Faith, Reason, and the Existence ofGod (Cambridge: Cambridge University Press, 2004), ix. We should exercise caution: Turner only purports to argue that he does "no more than to give further reasons of a theological nature why Christians should think, as a matter of faith" that his conclusion is right. This, however, is to make his argument belong solely to theology, while holding out the promise that it might also, or really does, belong to philosophy, independent of the question of faith...