Human Destinies: Philosophical Essays in Memory of Gerald Hanratty

Chapter Eight: Philosophical Sources of Aquinas’ Quarta Via

e i g h t Philosophical sources of aquinas’ Quarta Via Patrick Masterson in his “fourth way” of showing that God exists, aquinas argues for the existence of an absolutely supreme being from the degrees of perfection observed in the things about us: the fourth way is taken from varying degrees which are found in things. For among things one finds that some are more and less good, true, noble, etc. But more and less are predicated of different things according as they approximate in their different ways to something which exemplifies [the predicated perfection] supremely. For example, that is more hot which more closely resembles that which is hottest. there is, therefore, something which is truest, best, noblest , and, consequently, the greatest being. For what are greatest in truth are greatest in being, as is stated in Metaphysics 2. But what is declared to be the highest instance in any class of things is the cause of everything that belongs to that class; just as fire, which is the greatest instance of heat, is the cause of all hot things, as the same book 197 198 Patrick Masterson observes. there is, therefore, also something which is the cause of the existence, and goodness, and every other such perfection of all beings, and this we call God.1 it is generally acknowledged that the fourth way is the most controversial of st. thomas’ arguments for the existence of God. Philosophers differ not only in their exposition of the argument but also in their interpretation of the text in which it is outlined. For instance, those, such as etienne Gilson, who favor an argument in terms of exemplarism maintain that the part of the text which contains an appeal to efficient causation is of secondary importance and not essential to the proof.2 to clarify this issue it is worthwhile to consider some of the more important philosophical sources of the argument, which extend back to the philosophy of Plato. indeed, it has been maintained that “the proof is not only characteristically Platonic, but is also consciously derived from Platonic sources.”3 Whatever we may decide about the accuracy of this observation, it is certainly true that in an earlier work, where he proposed an argument similar to the fourth way, st. thomas refers to Plato as a source of his argument.4 Consequently, we begin our outline of the sources of the fourth way with reference to the philosophy of Plato. However, i think it would be a mistake to consider this famous Quarta Via as of merely historical interest. Certainly it has had a record of checkered evaluation—often dismissed as a Platonic illusion, a confusion of the real with the conceptual, or too easily accepted as providing immediate evidence of the existence of infinite Being as the obscurely intuited prerequisite of any affirmation of finite being. in fact, however, the text focuses attention on a central theme of aquinas ’ philosophy, namely, the analogy of being which embodies a powerful “cipher” of the sort of asymmetry which characterizes the relationship between God and the world. i believe that the proof, considered in this light, provides a “way” for a convincing argument for the existence of God as the ultimate foundation of the analogy of being. it provides an illuminating cipher of the asymmetrical transcendence of God vis-à-vis creation, which in turn, by way of indirect Philosophical sources of aquinas’ Quarta Via 199 causal argument, makes sense of the asymmetries which characterize the analogy of being. in my recent work The Sense of Creation, taking account of the historical background indicated below, i have described how such an argument can be elaborated.5 Plato according to Plato, there exists an ideal world of absolute perfections, and our judgments concerning degrees of perfection are possible only in virtue of a reference to this ideal world. He does not propose to prove the truth of these assertions. rather, they are offered as hypotheses which, if granted, validate his general philosophical position. in the Phaedo he writes: i turn back to those oft-mentioned things and proceed from them. i assume the existence of a Beautiful, itself by itself, of a Good and a Great and all the rest . . . and if someone tells me that a thing is beautiful because it has a bright colour or shape or any such thing, i ignore these other reasons—for all these confuse...