"In modern parlance, we hear the quotation marks if we say that objects under gravity 'know' where to go, and think of the verb as metaphorical. For Aquinas, too, such a use of 'know' would be unusual. But the extension of meaning would go beyond metaphor. The world itself, for Aquinas, exhibits an ordered series of harmonious structures, repeating on different levels and in different aspects: he calls their relation analogy. If you insisted that to recapitulate in language an analogy between crystals and minds was to equivocate, Aquinas would reply with a distinction: some equivocations mislead; this equivocation is strictly appropriate. Refuse to admit it, and you are blocking the light, the light by which things are enlightening the mind. That is the light of reason, of ratio, of appropriate proportion or structure in the world and in us.
"For Aquinas, all kinds of knowledge—especially Aristotelian scientia—depend on sources of light, on smaller revelations. First principles are manifestations of forms in the world, joining in one that which idiom divides, namely the form that inheres indifferently in minds and things. Each Aristotelian science is thus originated and individuated by its formal rationale or light. If you understand frogs, then you get light from frogs that gives rise to frog science in human minds. If you understand frogs, that also shows that frogs manifest frog-light, the first principles of frog, that give rise also to followable frog-structure in frogs themselves. That is also science, the science in frogs. The science in frogs gives light, and the science of frogs appears in the light. The more you attend to the first principles of frogs, the better science you have. The more you attend to frog-light, the more scientific your discipline is. The more something is revealed, therefore, the more scientific it is. Theology is no exception to that rule. Theology exemplifies that rule. Theology is for that reason not science by disciplinary extension; theology is science par excellence."
Eugene F. Rogers, Jr., "Thomas Aquinas on knowing and coming to know: the beatific vision and learning from contingency," in Creation and the God of Abraham, ed. David B. Burrell, Carlo Cogliati, Janet M. Soskice, and William R. Stoeger (Cambridge: Cambridge University Press, 248-249 (238-258). For Rogers' comments on the true "distinction between the science that is sacred doctrine [(which, 'at least in this life, . . . is a science without scientists' (255))] and the sciences that are natural," see pp. 254 ff. (1) "Knowing," or Aristotelian epagoge (insight), is characteristic of "only God and the blessed in heaven" (238 ff., 256; "Aquinas recognizes that there is something so teleological about epagoge that it is not quite human" (241), and "troubles and disrupts Aristotle's commitments to teleology at several turns" (240)). Here below we have only (2) "coming to know," or the gradual but systematic exploitation of the contingency unattended to by Aristotle. "Retroduction, or contriving experiment, is [Thomistic] ethics applied to matter: it tests the character of things" (244). Etc. Aquinas as a thoroughly modern scientist. Brilliant. A tour de force. Worthy of a third or fourth read.