Reflecting on 21 Centuries of Faith

To Be or not To Be a Thomist is the Essence of the Question

The Trinity and the Actus Essendi

In the April 1998 edition of the Thomist, Fr. Brian Shanley, O.P. (then Sub-Prior at the Priory of the Immaculate Conception in Washington, DC), considered the nature of Analytical Thomism and its place in current theological and philosophical circles.  During the conversation, he shares that there is hope for Analytical Thomisn but questions what is the foundational tenet that makes someone a “Thomist”.  He states,

“There is cause for optimism then about the stimulus to Thomism that could come from Analytical Thomism. As noted in this discussion, however, the major cause for concern is metaphysical. At the heart of Aquinas’s philosophy is his understanding of being as ultimately rooted in esse as actus essendi. This does not fit with analytical metaphysical dogmas. Here then is where the ultimate test of allegiance lies. It is possible, of course, to be an analytic philosopher who offers interesting readings of Aquinas without any commitment to his doctrine of being. But I would not call such a one a Thomist, nor, I presume, would he call himself one. What I am arguing is that to be a Thomist of any stripe requires some primary commitment to Thomas’s metaphysics; without that commitment, one may be an interpreter or even a specialist, but one is not a Thomist. It is a matter of debate, of course, what other doctrines of St. Thomas one must adhere to in order to be a Thomist and surely the items are broader than the metaphysics of esse. But however one draws the Thomistic circle, the core must be esse in St. Thomas’s sense, not Frege’s.”

The question of esse or being has been a contentious issue no doubt findings its roots in DeCartes and his progeny.  For those who are unfamiliar with St. Thomas’ understanding of the actus essendi, the following is a great summary found on the Actus Essendi blogsite:

The expression ‘actus essendi’ is a technical term used by Aquinas in its restricted meaning. ‘Actus essendi’ is the metaphysical principle that goes ‘side by side’ with the metaphysical principle ‘essence’ in a subsistent extramental thing.

Three points of reference are indicated here. One, the real finite thing itself existing in the external world; another, the ‘essence’ which makes the thing to be what it is; and yet another, the ‘actus essendi’ which places both the thing with its ‘essence’ in actual existence.

In the real world ‘essence’ and ‘actus essendi’ are inseparable metaphysical principles. The metaphysical principle of ‘actus essendi’ always appears instantiated in an ‘essence.’ And the ‘essence’ of the thing is what put limits to the thing’s participation in ‘actus essendi.’

The doctrine of the actus essendi appears at every turn in the philosophical and theological writings of Aquinas.

Still Aquinas is emphatic in saying that the metaphysical principle of the actus essendi is inseparable from ‘essence’.

At times Aquinas’ reflections concentrate more heavily and almost exclusively on the side of the metaphysical principle of ‘essence,’ but often his reflections rely entirely on the metaphysical principle of actus essendi. Nevertheless, throughout his writings, Aquinas crosses from the plane of ‘essence’ to the plane of the actus essendi and vice versa with remarkable facility.

The task of disentangling the nuances in doctrine he thus generates is not an easy one.

For Aquinas, the ‘act of being’ is the most profound perfection of a thing; it is an internal incommunicable metaphysical principle inseparable from the thing itself, from the ‘essence’ of the thing, and from anything that exists in the thing. No ‘essence’ actually present in nature makes itself known to the intellect without simultaneously making known its proper participation in ‘act of being.’

Orestes J. Gonzalez, “The metaphysical principles of ‘essence’ and ‘act of being” Actus Essendi Electronic Journal, Entry 01-0084.

Understanding this metaphysical principle is key because it sets the tone and exists as the foundational principle that all further arguments will build upon.  I would like to consider this over the next week and would invite all those who would like to further the discussion to do so.

5 Responses to To Be or not To Be a Thomist is the Essence of the Question

  1. Joe says:

    Interesting article. It really is hard to find someone who, without having taken philosophy, understands Aquinas’ metaphysics of being. What is even harder to find is another system of thought that can explain it any better.

  2. Comments from scholars are always welcome in the ‘Actus Essendi’ blog.

    Go to

  3. Orestes J Gonzalez says:

    Comments from scholars are welcomed in the ‘Actus Essendi’ blog.

    Orestes J. Gonzalez

  4. Joe says:

    Will take a look at your blog, when I get a chance.

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