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Thomas Aquinas: Pinnacle to Obsolescence in 200 Years and Why It Matters

Aquinas knew there was something prior to essence and being. Western culture lost sight of it.

The Summa (lest the reader think I'm amazing (chuckle): Volume V is still in cellophane 

1545. The city of Trento, in today’s northern Italy. The Council of Trent. The Bible was placed on the altar. Next to it, the officials put Thomas Aquinas’ Summa Theologica to symbolize the Catholic Church’s reverence for the Saint’s work, the greatest of the Catholic philosophers and Scholastics.

It may have been his high watermark. Less than 200 years later, Christian Wolff, the world’s leading philosopher immediately before Immanuel Kant, published his complete lectures. Scholasticism had fallen out of favor by then, but Wolff sought to preserve it and give it a place. The exemplar of Scholasticism chosen by Wolff?

Francisco Suarez (1548–1617).

Not Thomas Aquinas (1225–1274).

To Wolff, Suarez was not only the latest of the Scholastics, but the deepest and most profound of them.

And Suarez was an essentialist. Just like Wolff. Just like every philosopher of the time: Bacon, Descartes, Fenelon, Leibniz, Spinoza. They were all essentialists.

And all of them had forgotten that the truly greatest among Scholastic philosophers, Aquinas, was an existentialist.

Essentialism, Existentialism, and Priority

From ancient Greece through modern philosophy, it was widely accepted that essence took priority over existence.

What does this mean? Basically, this: to know something exists, you need to know its essence. Therefore, essence is prior to existence. If you believe this, you’re an essentialist. If you believe existence is prior to essence, you’re an existentialist.

Essences are those things that define a class of things. If you find the thing that distinguishes one class from another, you’ve found its essence. For the class “elephant,” that thing might be its trunk. For humans, that thing is the rational faculty. Once you discern a trunk or a creature with a rational faculty, you identify the existence of an elephant or a human.

Essences, in other words, are fundamentally definitional. They define classes of things. If you have Essence X, you are expected to look like, behave like, a thing with Essence X. You are, in other words, to be like a thing with Essence X. “To be” is roughly the equivalent to “to exist,” hence the idea that existence comes from essence: Once you know a thing’s essence, you can know its existence.

Essences can also bleed into, and become confused with, characteristics that Aristotle called “accidents.” These are things that help define an individual within a class. Both essences and accidents are definitional. So:

The rational faculty (a common trait of all persons) on Person A: Essence.

The six feet of height (an individualized trait) on Person A: Accident.

Aquinas’ Existentialism

Essence might be queen and prior to being, but the act of existence is king and prior to all.

Thomas Aquinas would’ve agreed with the fundamental point of the essentialists from above: If you have Essence X, you are expected to be like a thing with Essence X. “To be” is roughly equivalent to “to exist,” hence the idea that existence comes from essence.

But he penetrated deeper.

It’s not easy to understand, so read the following carefully. You may need to read it, like, 20 times and contemplate it for eternity (I’m still unpacking it in my mind and I’ve been thinking about it off-and-on for years):

Aquinas drew a distinction between “being” and the “act of existence.” For Aquinas, the fundamental meaning of what it is to be a being (ens) is to be a haver, or possessor, of the act of existence (esse). He used this analogy: A man is a runner by his act of running. Similarly, man is a being by his act of existing.

The act of existing was, for Aquinas, supreme . . . prior to all else. The essentialists might be right: essence is prior to existence because we know a thing’s existence by its essence, but there is something prior to both: the act of existence.

Or to put it more precisely, Aquinas would concede that essence is prior to being because we know a thing’s being by its essence, but there’s something prior to both: existence itself.

Aquinas’ distinction between being and existence is still debated. (1) Some philosophers agree with him; (2) Some philosophers don’t think there’s a difference between being and the act of existence; (3) some philosophers are agnostic on the point but don’t see a need to add existence to being.

I believe Aquinas was obviously right, but I understand why some philosophers don’t see a need to add the act of existence to being. In other words, I put myself in category (1), reject category (2), and respect category (3). It’s axiomatic to the point of absurd common sense that, in order to be a being, you must have existence (i.e, be engaged in the act of existence), so it’s not even worth talking about. That’s why the philosophers in category (2) are simply wrong but why I appreciate the position of the philosophers in category (3).

But here’s where I part company with (3): the impact of essence. Essence is prior to being, just like the essentialists say. But it’s not prior to existence (or, more accurately, “the act of existence”). If we fail to acknowledge a difference between existence and being, we give essence priority to all else, making it queen, so to speak, because the fundamental point of the essentialists (that without essence, we can’t know being) can’t be denied. But that would give essence too much importance or power because there is something even prior to being and essence: the act of existence itself.

Essence might be queen and prior to being (which we might call the “prince,” since we only know being from essence (queen)), but the act of existence is king and prior to all.

But the concept of "the act of existence" was disregarded after Thomas Aquinas, slowly falling to obsolescence by 1600.


I believe that the act of existence’s obsolescence is the defining trait of modernity, much to our detriment. I also think our culture has been groping for the past 200 years to reclaim it, in some form or fashion.

Exhibit A: Our interest in the Tao. The Tao, as explained in previous columns, is (I believe) the “act of existence.” Our culture is acutely interested in it. In the Tao, we perceive something that is missing.

The reality of the Tao, why it went missing in western culture, the effects, and our efforts to reclaim it will continue to be a theme of these Monday columns.

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