Lectures in 1964:
Cf. Thomism & Mathematical Physics.
Interestingly, although he says quantum is nothing like anything we have seen before, he later goes on saying that we can understand it in analogy to what we do know (cf. The interpretation of St. Thomas Aquinas of Aristotle, Physica 191a7-8: "The underlying nature is known by analogy.", available from ProQuest Theses). New knowledge must be party based on what we already know (cf. Expositio Posteriorum, lib. 1 l. 1 n. 1: "The need for pre-existent knowledge in all learning").