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Monday, August 20, 2012

0239: Aquinas’ Five Ways and Aristotle (II)



Entry 0239: Aquinas’ Five Ways and Aristotle (II)


It is generally accepted that Aquinas' Five Ways of proving the existence of God have their ultimate source in Aristotle. Aquinas is not the originator of the arguments. In this regard, Fergus Kerr offers the following remarks:

“One thing is not always made clear: Aquinas does not regard the Five Ways as his own arguments, nor does he regard them as arguments which might or might not work. Rather, he regards them as arguments that already have worked. In the parallel discussion in the Summa contra gentiles he takes much more time and trouble but even there it is surely plain that he is only rehearsing what he regards as ancient and familiar arguments.

“Admittedly, when Aquinas spells out the First Way, based on the obviousness of change in the world, he does not explicitly refer to Aristotle; but the parallel passage in Summa contra gentiles (I, 13) shows clearly enough that he knows that Aristotle is the source of the argument. The Second and Third Ways, based on efficient causality and the fact that some things have the possibility of being or not being, respectively, have equally clear roots in Aristotle.

“The Fourth Way, invoking degrees of being, goodness, truth, and so forth, the only one in which Aquinas cites Aristotle explicitly, is, paradoxically, as it might seem to us, distinctly Platonist in origin and inspiration. In fact, for all his involvement in the retrieval of Aristotelianism, it has been shown in the last fifty years or so that Aquinas remains profoundly indebted to Platonism.

“No authority is cited for the Fifth Way, from design or teleology, but the brief exposition recalls the most ancient and persistently popular argument of all, dating back to Plato and the Stoics as well as to Aristotle. While of course most of Plato’s texts were unavailable, and there is little sign that Aquinas knew much of the Stoic literature at first hand, it is surely clear that he takes it for granted that he is expounding a very familiar argument.” (1)

(1) Fergus Kerr, “Theology in Philosophy: Revisiting the Five Ways,” International Journal for Philosophy of Religion 50 (2001): 115–130.