Abstract

If Aquinas lived today, he would accept that Darwin was correct, at leastas to the broad lines of his theory, namely, that the unfit are differentially eliminatedand chance is involved in the origin of new species. Aquinas in fact offered a similarexplanation for what he believed were spontaneously generated organisms. I intendto show that extending this sort of explanation to all species in no way affects thekey steps in the Fifth Way (e.g., “those things which lack cognition do not tendto an end unless directed by someone knowing and intelligent”). Thomas himselfprovides us with the crucial points for bringing evolution by natural selectioninto accord with the Fifth Way, including the distinction between a maker anda designer (builder vs. architect), an explanation for organisms’ imperfections interms of material necessity and secondary causality, and an account of the role ofchance in the world.