I was struck by St. Thomas’s account of the ultimate interior end of the universe:
Now, in the order spoken of before, in which the rational Plan of divine providence is observed, we have said that the first is the divine goodness as the ultimate end… second is the numerical plurality (numerositas) of things, for the constitution of which there must be different degrees in forms and matters…
And so immediately under the order to God as an extrinsic principle, the ultimate good is the numerousness of things, a numerousness that is most of all verified in the division of one species from another by form. Note that, in this context, the numerousness of species abstracts from time – extinct species would thus be a contribution to diversity in the sense St. Thomas is speaking of here. Again, when we speak of a species here we abstract from the division of species and subspecies, and other such precisions.
Processes like selection and drift are unintelligible and superfluous except in relation to this sort of diversity, and so must be understood in relation to the chief interior end of the universe. Notice that this is a far more intimate and profound union between creatures and the creator than is usually posited by theistic evolution. Theistic evolution might posit intentional action in the making of the first species, or in occasional actions correcting or directing the process; but when we consider evolution as teleological according to the good St. Thomas suggests, it is not merely connected with an end so far as the need for the first living thing to arise (in which case evolution would only be teleological in the principle it arises from) nor is it only connected to intentional action at the occasional moments where God might step in and direct it; rather, it is teleological so long as there is any diversity in species at all, that is, always and in its own intelligible structure. Moreover, this end is not simply any old end – but the ultimate intrinsic end of the universe itself. Does theistic evolution ever connect evolution to a good of the universe, still less the greatest intrinsic good of the universe as such?
All this is perfectly consistent with any particular instance of selection and drift being utterly unpredictable as to its particular result. The goal that the process is working towards is not this or that particular species, and everything that atheist philosophers say about the utter-chanciness, unpredictability and absence of particular design in the process is true. It’s just that the goal is far more general, obvious, and separated from any particular instance of selection – which considered in themselves are each completely random.