The Thought of Thomas Aquinas

"I was an atheist for about ten years, and I only became a theist in the early 2000s. The reason I moved from atheism to theism was in large part because of my study of Thomas Aquinas. I got into the study of Aquinas by way of preparing for lectures that I was giving in philosophy classes. I wanted my students to understand why anybody would have found arguments like Aquinas’ convincing in the first place, even though I myself at the time did not. So, I got back into the secondary literature in the course of preparing my lectures. I came to see Brian Davies’ book on Thomas Aquinas as one of the best examples of this literature. It’s one of the most lucid and thorough yet succinct summaries of Aquinas’ thought. Davies explains Aquinas in a way that is not only clear but is also written from the approach of someone whose training was in analytic philosophy. Davies is really someone to read for any analytic philosopher who wants to understand Aquinas. I have found this book really useful from that point of view. He explains very lucidly what Aquinas has to say about issues like the ones we were talking about earlier from the first part of the Summa Theologiae , but he also provides a general overview of what Aquinas has to say about other subjects as well. For example, about distinctively Christian doctrines such as the Trinity and the Incarnation and what Aquinas has to say about issues of philosophical anthropology, free will , ethics, and what contemporary philosophers would call philosophy of mind . In general it provides the best overview of Aquinas’ thought that is available these days and, as I say, one that is especially useful to someone whose training is in analytic philosophy. The way that Aquinas divides up the territory is that he thinks there are some things that we can know about God through purely natural reason. From a modern reader’s point of view, it might be surprising just how much Aquinas thinks we can know in that way. We can know not only that there is a God — in Aquinas’ view this can be strictly demonstrated through philosophical arguments — but we can deduce a great number of the divine attributes: that God is all-powerful, omniscient, outside of time and space, and so on. There are other things about God’s nature, however, that in Aquinas’ view cannot be known through philosophical reasoning alone. They could not be known simply through applying our natural powers. If we’re going to know them, then, we need to rely on special divine revelation. God has to reveal them to us through some prophet or sacred text or the church, for example. The doctrine of the Trinity and the doctrine of the Incarnation would be two examples of this. Now, does that mean that Aquinas thinks that these are not ideas that are susceptible of rational investigation? No. True, he thinks that we can only know about them through divine revelation, but, there are two things that have to be emphasised here. First of all, Aquinas would not deny for a moment that when we ask ‘How do we know that these doctrines have really been divinely revealed?’, we have to be able to give a rational answer to that. He doesn’t think that the fact that divine revelation has occurred is itself something that we have to appeal merely to faith in order to know about. He thinks that you need to be able to give rational arguments for the conclusion that an act of divine revelation has actually occurred. So even what he has to say about distinctively Christian doctrines doesn’t float in mid-air without any rational foundation. He does think that we can know these things only if God reveals them, but he also thinks that we ought to be able to give some rational argument for the conclusion that these doctrines really have been divinely revealed. And he thinks that there are such arguments. “Aquinas doesn’t think that the fact that divine revelation has occurred is itself something that we have to appeal merely to faith in order to know about. He thinks that you need to be able to give rational arguments for the conclusion that an act of divine revelation has actually occurred.” And once we have these doctrines through divine revelation, we can go on to investigate them rationally. We can give a philosophical analysis of the doctrine of the Trinity and ask about the content of the doctrine. What exactly is it saying? Does the doctrine contain any self-contradiction that would make it objectionable from the point of view of reason? Aquinas thinks that we can show that there in fact is no contradiction. Even if he also thinks that human reason can never entirely penetrate it, human reason can show that any attempt to show the doctrine to be somehow incoherent or self-contradictory doesn’t succeed. Even though reason couldn’t discover doctrines like the Trinity on its own, it nevertheless can know that they are divinely revealed and it can rationally investigate them once they have been revealed."