The Metaphysics of St. Thomas
in one easy but not simple lesson

( You think we are kidding, right?)

We hear the word metaphysics today often connected with New Age philosophy, but the way it is used here is in its classical sense. Metaphysics is the heart of a philosophy rooted in the ancient Greeks, especially Plato and Aristotle, whose insights made their way into the Catholic Church through men like Augustine and Thomas Aquinas. It was Thomas Aquinas who gave it a definitive form, and it was his metaphysics that was renewed in the middle of the 20th century by scholars by Etienne Gilson and Jacques Maritain.

Therefore, this is a philosophy that the Church has lived with for many centuries and which it has shaped to be an instrument of theological exploration. It is a living tradition of philosophical wisdom which we can become a part of today.

But I don’t want to look at the history of the metaphysics of St. Thomas. Instead, I would like to give you a taste of the insight that is at the heart of this metaphysics. This is a very simple insight that can be put down in a few lines, which St. Thomas does, himself, but it is so simple that it can be quite difficult to grasp. A large part of the drama of the various declines and renewals of Thomist philosophy hinge on the loss and rediscovery of this insight.

The metaphysics of St. Thomas is based on two central principles: essence and existence. And it is the relationship between essence and existence that is the key to the metaphysics of St. Thomas.

All around us are different kinds of things: apples, butterflies, and elephants. And we don’t confuse one with the other. What is essence? It is what a thing is. It is what makes a thing to be what it is. It is its whatness.

All around us are existing things. We have no doubt there are apples, butterflies, and elephants. They are certainly different, but they all exist. They are. Existence is the thatness of things in the sense of the very fact that they exist, or the isness of things.

Neither essence nor existence is hard to grasp, for both of these ideas emerge from our experience. They are two fundamental ways in which we can look at things. We can ask about the elephant, what is it? And we can assert about the elephant that it is. But we have to go deeper and explore the relationship between essence and existence.

One way to do this is to ask ourselves what makes a what to be a what, or what is whatness? What is the essence of essences? These are strange questions, to be sure, but ones that Thomas posed in his own way, and to which he gave a fascinating answer that was to revolutionize metaphysics.

An essence, or a what, is a certain capacity for existence. Different essences or whats are partial reflections or refractions of what it means to exist, to be, just like different colors of the rainbow are partial refractions of sunlight.

This is the heart of the metaphysics of St. Thomas in one simple lesson, but its simplicity comes from its depth, and we need to penetrate into that depth by meditating on the relationship between essence and existence if we are to grasp what it truly means.

Still a bit puzzled? Try the reading.

Now it is your turn to contribute to this discussion. Send us your questions and comments:

With regards to existence, it is better to say that existence is the "is-ness" rather than "that-ness" of beings. Jude Chua, Singapore

Your point about "thatness" is a good one. It is meant there in the sense that something exists, but isness will bring it out better, and so we will change it. The Editors

Esse is better brought out by "is", you know, esp. since esse is better as is-ness, than a "that-ness". Is-ness better captures the idea of "reality", whereas "that-ness" fails to do so. Further, that-ness or "that" might bring across the misunderstanding of existence (esse) as a "standing out there", which "existence", coming from "exist-ere", really means. Infact, to translate "esse" as "existence" is not correct, strictly, since existence, as was said above, is a standing out, whereas esse really means real-ness, and is better translated as "act-of-being" or even "is-ness". Jude

Thanks for your further remarks about esse. We think they are on target. What do you think about the question of how people can come to a sense of the isness of things without which a metaphysics like that of St. Thomas cannot really thrive? The Editors

Maritain and esp. E. Gilson both stress the intuition of being (esse) as the starting point of metaphysics, that is for sure. Hence for them, without this sense of esse, one would not know the "stuff" discussed in metaphysics, just as a blind man could never know what we mean by red and all other arguments involving this notion and its related terms. And especially since metaphysics is the science of ens qua ens, and ens is the composition of essence and esse, to not know what esse is is to not know a lot in metaphysics: at least half or more (to use quantitas metaphorically).

BUT. There is another reading of St. Thomas's esse which is not directly arrived at by intuition or any seeing or sensing, but by a slow process of study, by arguments and demonstration, separating concepts until we finally arrive at the concept of esse. In this way, the epistemic starting point of being is not seeing, but a laborious study beginning with physics and working towards metaphysics, by understanding reality using notions other than esse, and slowly arriving at other metaphysical notions, which then in turn are used to demonstrate by conceptual separation this notion called esse. This is the traditional reading of Thomistic metaphysics, and you will find Ralph McInerny of this persuasion. Hence in this case, one enters metaphysics towards esse, and not from esse into metaphysics, which is the above Maritain and Gilson way. In this second case or reading, i.e., the Ralph McInerny reading, it is therefore possible for metaphysics to "thrive" without this sense of esse, since the other terms are comphrehensible of themselves. Of course the summit is esse, but without seeing the top yet, the foundation still stands.  (Personally, I think they are both right: St. Thomas says being is the first object of the intellectus; now if being is the first object and all other notions are built on this, then unless we know implicitly what is esse, we cannot even argue or demonstrate, let alone argue from physics to metaphysics and so on. And since arguments presuppose esse, arguments do not themselves furnish esse; this leaves the possibility of some epistemic "seeing" to furnish that notion. Ergo, Maritain is right. However, if we all see esse but we are unsure whether what you mean by "esse" is the same as what I mean by the same "esse", then we must find some way of confirming that, and this is through demonstration, by proceeding from terms least ambigious to terms most ambigious. Hence proceeding from physics and physical terms, which we are more sure we use in the same way, we proceed to isolate what we mean by, ultimately "esse", and such other terms in metaphysics. Ergo, McInerny is also correct and also prudent. I think this is very important, because the common criticism of Thomistic esse is that every body claims to have been "caught alive" and to have seen esse but locate it in differing stages or use it to seemingly mean different seeings. Francis Cunningham, SJ, for example, criticises the real distinction on this count.)  However, if we follow Maritain, then as you have rightly said, it is hard to see how something can thrive which we do not know. Your question is a really good one. I haven't really got an answer as yet, although I have been thinking about it for quite a while. Jude

The intuition of being, or to put in other words, a keen sense of the primacy of existence in the metaphysics of St. Thomas, can be reached from two directions. Maritain, for example, describes various concrete experiences that can lead to it, but he also describes how it can happen "in via judicii," which is close to what you are describing as a slow process of study, etc. I suppose an analogy would be to the Rinzai and Soto schools of Zen.

BUT. It is reaching the goal no matter how it is done that is crucial, and this goal, as I said, is a sense of the primacy of the act of existence. If we don't arrive there, then the danger is to see the metaphysics of St. Thomas as a philosophy of essences. I don't see how it is possible for metaphysics to thrive without this sense of esse. And further, all the central terms of Thomas' metaphysics can only be comprehended in their fulness from the perspective of esse. Esse is not only the top of the mountain, it is the foundation, as well. While it is true we have to have a certain idea of being to reason at all, this being of common sense and the ordinary working of the intellect is not grasped in its full intelligibility, as it must be for metaphysics to exist. The history of the metaphysics of St. Thomas is a history of the discovery, then eclipse, and rediscovery of this central intuition of being. The real foe of Thomism and the reason why it has declined since the Second Vatican Council is the philosophy classroom where words rather than the intuition of being were primary. The Editors

How to contribute to this discussion

Reading: Essence and Existence