Contrary to popular belief, there is more than one type of Thomism. My own allegiance is to Aristotelian-Thomism, which holds to realism and teleology with respect to various metaphysical and ethical issues. Nevertheless, I remain intrigued by what's known as "Transcendental Thomism." This is not Thomism combined with presuppositionalism. Rather, it's an attempt to reconcile the conclusions of Thomas Aquinas with the methodology of Immanuel Kant. That's just a rough definition, but it'll do for now. One famous Transcendental Thomist is Karl Rahner.
What caused me to initially look into this other school of Thomism is a discussion I had years ago as an undergrad with my Ethical Theory professor. I questioned whether virtue ethics were really inconsistent with Kant's categorical imperative. He stated that it was, and that was that. Don't get me wrong; he was very polite about it. However, I wasn't convinced.
Let's take the Aristotelian mean (virtue ethics) between two extremes: cowardice and rashness. The Aristotelian mean is courage, or bravery. The coward shies away from acting when he ought to act. On the other extreme, the rash person goes out looking for trouble. A truly courageous person will act/step in/fight/whatever when appropriate. Now, why can't the categorical imperative be consistent with this? Wouldn't Kant agree that the best moral decision to choose is courage?
Of course, there are some inconsistencies between the two. Kant is famous for stating that one ought to tell the truth even if the whole world should perish, and no exceptions. The virtue ethicist, while acknowledging that lying is wrong, will make exceptions for a person's culpability. For instance, if one were living in Germany during World War II, and Nazis came knocking on his door, asking if he's hiding any Jews, then the homeowner ought to lie if he's hiding any Jews. Lying in this situation will potentially save the lives of these men and women, which is a greater good than telling the truth in this situation.
When it comes to metaphysics, Kant rejects the traditional arguments for God's existence first on the grounds that the noumena (what a thing is in and of itself) cannot be known. What we do know is phenomena (what we perceive). Kant also allows for a priori knowledge, or at least a predisposition toward allowing perceptions to be intelligible. He accepts a moral argument for God's existence, based on the pragmatism of moral accountability. However, I think the Transcendental Thomist can salvage the traditional arguments simply by limiting their application to the phenomenal realm. Take, for example, the argument from change:
1. Changing things exist. (Premise)
2. Changing things exhibit actuality and potentiality. (Premise)
3. No potentiality can actualize itself. (Premise)
4. There is a regress of potentialities being actualized. (Premise)
5. The regress itself exhibits potentiality. (Premise)
6. Hence, the regress cannot actualize itself. (From 1 - 5)
7. The only thing that could actualize an entire regress of potentialities is Pure Actuality. (Premise)
8. Therefore, Pure Actuality exists. (From 6 and 7)
The purpose of this post isn't to debate the merits of this argument. I've written many posts previously where I invite such debate and discussion. Rather, the point here is this: Kant rejects this argument because its premises make claims about the noumenal realm, the latter of which is unknowable. Now, there are two options the Thomist can take at this point. The first is to take the Aristotelian-Thomistic approach and reject Kant's insistence on there being an unknowable noumenal realm. The second is to follow how the Transcendental Thomists respond, which is to ask: so what? So what if the argument has no bearing on the noumenal realm? It can still be applied to the phenomenal realm, and one would be justified in accepting this as a sound argument for God's existence so long as it's justification is limited to phenomena.
In any case, these are just some of my inchoate thoughts. My favorite (extra Biblical) philosophers are undoubtedly Aristotle and St. Thomas Aquinas. However, I'd include Kant somewhere within my top five philosophers.