There's been some controversy around Intelligent Design (ID), and no, I'm not talking about ID versus evolution or ID versus some naturalistic explanation of abiogenesis. I'm actually referring to an in-house debate among theists about what ID entails. Was Thomas Aquinas an ID theorist? According to Edward Feser, no. Why not? Because Thomas Aquinas's design argument (the Fifth Way) is not mechanistic, whereas ID theories are perceived to be so.
However, taken more literally, Thomas certainly was an advocate of ID. He certainly believed that God, as the universe's Cosmic Designer, was (and is) an intelligent agent responsible for the order, regularity, purpose, and life in the world. What is underlying Feser's and others' objection is the metaphysics behind Thomas's ID versus contemporary ID, the latter of which even includes William Paley's view. On Thomas's metaphysics, God is Pure Actuality, which I've repeated probably a hundred times on this blog at least. As such, God is immutable. On contemporary conceptions of ID, God intervenes in the universe to "correct," as it were, the elements so that life emerges.
What I've just described as contemporary ID conflicts with Aristotelian-Thomistic (AT) metaphysics simply because God, being immutable, must have eternally planned the emergence of life with his perfect foresight. So, it's not as if Thomas would object to ID per se, but only the type of ID that requires a change in God and a purely mechanistic view of the entities being designed. For example, the human mind is not like a computer, the latter of which is mechanistic. Sure, the brain can be explained in some mechanistic terms (but not all), but the mind is not the brain. What's a tad poetic about this is that most ID theorists, if they're Christians, Jews, Muslims, etc., agree with this, but their non-AT interpretation of ID doesn't account for this.