What are the fundamental teachings of Thomism?

Now, given what has been thought-through about Thomism and Thomists in the introductory posts, the next most obvious question is one related to the fundamental teachings of Aquinas and Thomism. What do Thomists more or less universally hold to be the case: 1) Are there particular teachings that are fundamental to Thomism? 2) In what sense might they be fundamental? 3) And what are they?

To answer the first, we must begin with the second: In what sense do I mean ‘fundamental’? By fundamental we should think of teachings that are both foundational and necessary, for all that is truly grounding in a foundational sense (regardless of whether we are thinking of a building or a theory) is also necessary to everything subsequent in the superstructure. And by necessary, we should think of teachings whose removal would lead to the undoing of the whole theoretical structure (through the de-structuration of its coherence and unity).

With respect to Thomism, then, are there teachings that undergird the whole theoretical structure, in all its complexity, with all its parts? To this question, we can confidently say, ‘yes,’ without invoking any controversy.

We could immediately here think of the concepts of act (actus) and potency (potentia); the real distinction of being (esse) and essence (essentia); the correlation of form (form) and matter (materia) in material being; the division of being into various modes of being (modus essendi) and predication (modus praedicandi); with a first division into the contrasted categories of substance (substantia) and accident (accidens); and finally, the analogy of being (analogia entis), that part of the theory that undergirds and embraces the whole conceptual framework.

Each of these, and all together (since they are all interconnected), are surely foundational for Thomism, and all are mentioned in the introductory paragraphs of the ‘24 Thomistic Theses’—a set of teachings collated for and endorsed by the Catholic Church early in the 20th century. Though this endorsement is not an infallible pronouncement of the Church, it certainly places emphasis on these teachings as worthy of close attention, and even if one is not a Catholic, given the seriousness with which Catholicism takes philosophy in general and Thomism in particular, it is worth taking note of this collection of teachings.

Let us here look briefly at each by approaching them from the coordinating perspective of the Thomistic understanding of being (esse), which is arguably the most foundational notion in Aquinas’ thought. This will reveal something of their foundationality as well as their closely interwoven character. And though we will cover each in greater detail in subsequent posts (as well as other foundational teachings), a short introduction here will have to suffice.

For Aquinas, ‘being (esse) is the actuality of all acts and, therefore, the perfection of all perfections’ (Summa theologiae I, 4.1, ad 3; among others). Now, it is hard to imagine a more programmatic statement. Should we take it with all seriousness, we immediately see that everything isshot throughwith being—in all ways, through all dimensions, under all aspects—so that, for Aquinas, being is both first and last in all things. As such, being is the most basic of Thomistic principles, since it affords the actualization of the whole of what we call reality (derived from the Latin for thing ‘res’), here understood as the summation of all things in the harmoniously ordered whole of everything existent.

Simply speaking, being (esse) is the basis of everything we say ‘is.’

The Latin ‘esse’ is here translated as ‘being,’ a participle, even while in Latin it is the infinitive form of the verb. Thus, it would be better (i.e., more literal) to translate ‘esse’ as ‘to be,’ which would then mean that the programmatic statement of Aquinas would be better translated as ‘to be (esse) is the actuality of all acts and, therefore, the perfection of all perfections,’ from which we then see that ‘to be’ itself is the most basic principle undergirding Aquinas’ whole theoretical framework.

Therefore, for Aquinas, reality itself is nothing less than dynamic actuality. ‘To be or not to be,’ truly is the question, the first question, both most foundational and most important.

Now, included within the domain of reality is both Creator and creation, inasmuch as both are existent realities, even while the being of God and the being of creatures are radically distinct in each case. This differentiation is rooted in a closely connected teaching of Aquinas that ‘God is His own essence’ and ‘His own being’ (ST I, 3.4, co.), so that being and essence are actually coincident in God, while everything created, precisely because it is created, is necessarily a being-essence composite, so that being and essence are really distinct in all creatures.

From this we can see that being and essence stand in an act-potency relation with respect to one another, where being is understood to be the principle of actuality (as a principle of ‘what is’), and essence the principle potentiality (as a principle of ‘what can be’). When an act of being (actus essendi) actualizes a specific essence, we then have a being-essence composite, an existent thing that possesses actuality (and thus exists as something real), and a corresponding unity (an act-potency unity, which is unity of the highest kind).

Following Aristotle, Thomism calls these existent things ‘substances (substantiae),’ where substance identifies the primary mode of being, since substance has being in itself and thus ‘sub-stands’ all other modes of being. These other secondary modes of being are called ‘accidents (accidentia),’ since they have being in another inasmuch because they require an actual foundation in substance in order to exist. There are nine accidents enumerated by Aquinas, following Aristotle, they include quantity, quality, relation, action, passion, place, time, posture, and having.

With this basic description of reality already in place, Aquinas then proceeds to show that there is also another kind of act-potency correlation that is foundational to the world of material things. Unlike immaterial substances, which are being-essence composites only, material substances are a further composition of form and matter, where form provides the principle of actuality and matter the principle of potentiality. (In this way, we see already, in an initial way, the basic agility of the concepts of act and potency, in their applicability to many things.)

Then, for living material substances, the form is a special kind of form, a living form that now receives a special name, namely, soul (anima). Like form the soul is the principle of being, unity, and determination of its substance, but unlike form, the soul is then also the first principle of the life of the substance, because the soul is the form of a living material substance—and thus also the form of the body. This latter Thomistic principle is an incredibly significant teaching that is foundationally important for everything anthropological.

Now, above we noted that God and creature are radically different, since ‘to be God’ (here signifying the divine essence) is simply ‘to be’ (here signifying the divine actuality), whereas ‘to be a creature’ (here signifying the creaturely essence) is not simply ‘to be’ (here signifying the creaturely actuality). This means that while God exists by necessity, inasmuch as He possesses an received and unlimited act of being (actus essendi), creatures do not exist by necessity and are, rather, radically dependent upon their Creator, inasmuch as they possess a received and limited act of being (actus essendi).

This is a big difference.

Yet God and creatures are not so different that no relation and similarity exists between them. After all, since creatures are made by God, they must not only be related to Him, but must be like Him in some or other way. This follows upon a basic metaphysical principle, that all causes make, and can only make, effects that are in some way like themselves. Simply stated, causes can give only what they have; and effects can receive only what their causes can give. For example, fire as an effect is like fire as a cause, and heat as an effect is like fire as a cause; and even though fire and heat as effects different in each case, and even while heat less perfectly resembles fire, both are nonetheless like fire as their common cause. Thus, all creatures are related to God as their cause, and all creatures are like God as their cause.

This then brings us right to the final foundational teaching of Aquinas’ philosophical schema (at least in terms of what can be detailed in a short blog-post), that of the analogy of being (analogia entis). For Thomism, the analogy of being explains the way creatures are both related to and similar to God, via their common possession of being. Since creatures have received being from their Creator, creatures are radically dependent upon Him for all that they are and all that they have; again, since creatures have received being from their Creator, creatures have a similarity to Him in all that they are and have via their very participation in being. And this is true even though being is possessed by the creature and the Creator in radically dissimilar ways, with the creature possessing being as received and limited, while the Creator just is being by essence.

Therefore, the creatures similarity to God through their possession of being also inaugurates their fundamental differentiation from God, in the great dissimilarity of the way being is differently possessed by creatures in contrast to their Creator. As is now clear, whereas creatures possess being in a dependent and finite way, the Creator possesses being in a self-dependent and infinite way—or rather, better stated, God just is ‘subsisting being itself (ipsum esse subsistens)’ (ST I, 4.2, co.; among others). The analogy of being then reveals that while creatures possess a basic similarity to God, through their possession of being, creatures possess a still greater dissimilarity to God, through the finite way they possess being in contrast to the God’s infinite plenitude of self-necessary being.

Then, in accord with God’s possession of being by essence, and in correspondence to His universal causality, every true perfection found in created reality bespeaks of this same perfection in the Creator. Yet, though these perfections—such as unity, truth, goodness, beauty, nobility, justice, mercy, etc.—are found in creatures in received and limited ways, just like they possess being, we must come to understand these same perfections as essential and infinite in God. Whereas creatures may possess justice and mercy together, in distinct and partial ways, God just is justice and mercy, in a unified and fulsome way.

In just this way, the analogy of being reveals itself to be the Thomistic conceptual framework that embraces absolutely everything, both Creator and creation, first in their basic relation and similarity, and then, simultaneously, in their still greater distinction and dissimilarity.

This brings to a close our summary of the fundamental teachings of Thomism. We have seen—even if only in outline and without demonstrative clarity—that there are certain teachings so basic to Thomism that they are inextricably interwoven with the whole theoretical framework (even while we can also grant that this list is not exhaustive). In later posts, we will look at each teaching in itself (while also looking at several others), for much more reasoning is required to substantiate each, or even just to properly understand them in a basic way.