The Substantiality of the Person
At the dawn of the medieval era, a Christian philosopher-theologian, Anicius Boëthius (480–524 AD), was the first to formulate a philosophical definition of the person. After the term had been incorporated into the definitions capturing the two fundamental mysteries of the Christian faith, the Trinity and the Incarnation, the Christian West was set the task of venturing toward an ever-deeper grasp of its meaning—the meaning of being a person. Taking up this task, Boëthius articulated the first systematic definition of the person in a formulation suitable to its attribution to human, angel, and God. By reasoning according to the philosophical heritage of Plato and Aristotle, Boëthius concluded that there are three features essential to the being of the person, namely, substantiality, individuality, and rationality. Accordingly, Boëthius defines the person as ‘naturae rationalis individua substantia, an individual substance of a rational nature.’*
As a metaphysical definition, it not only articulates the essential features of the personal nature, but it also specifies the person as distinct from all other realities, for this is precisely what good definitions do, provide all essential features while distinguishing the reality from all else. The definition is evidently not a person, and nor does it attempt to give us the whole mystery of being a person, but it does give us intellectual access to the person. It is a lens through which we can more adequately identify the the person, while also coming to see the person more fully, more completely, and more clearly. The definition is then a means by which we come to a deeper understanding of the reality, but it is the reality itself that we must attend to when we seek this deeper understanding. Now, like the Aristotelian identification of the human as rational in his definition of the human species as ‘rational animal,’ the Boëthian definition also focuses on rationality; yet, unlike the Aristotelian definition, which attends only to the species classification within the broader cosmic whole, the Boëthian definition highlights the significance of the substantiality and individuality of the person together with the rational nature.
This differentiated focus is of great importance. Some of this comes out in the present essay on substantiality, some in the next on individuality. For now, we need only note that Boëthius, together the whole medieval tradition following him, understands the person to be something substantial. Simply stated, the person is a substance, and their is dignity in being a substance.
As a substance the person possesses the kind of being that is primary in the order of being. This primacy is seen in the way that substances underlie all other modes of being, while they themselves do not have anything else underlying their own being. Substances literally sub-stand everything else, and this is precisely why they take the name ‘substance.’ Now, while this might not appear to be so important, it is actually of first significance, for we attribute the term ‘substance’ to whatever reality we consider to be the most important, as both most foundational and most vital. All other modes of being—whether quantity, quality, relation, etc.—depend on the presence of their underlying substance for their own characteristic mode of being, which makes them secondary to the primacy of substance. Now, the human person is such a being, a substantial being, not an accidental being. Hence, we can say that persons are the kind of being that do not depend on anything else for their existence, but stand in being with an existence that is entirely their own (notwithstanding the reliance of creaturely persons on their Creator).
The Brownshill Portal Dolmen of Carlow, Ireland, symbolizing solidity and eternality, both of which follow upon the substantiality of the person as a subsistent substance bearing rationality.
However, we must go still deeper to understand all this correctly. When we identify the person as primary in this way, our identification does not yet have enough focus on the existential. It does not yet attend to the existential ‘weight’ of being a person with enough force. Therefore, when Aquinas adopts and endorses the Boëthian definition, he subtly adjusts its formulation to hone in on the factuality of existence (‘ex-sistere, to stand forth’) by finally defining the person as ‘a subsistent individual of a rational nature’ (ST, I, 29.3, co.). By using the term ‘subsistent’ instead of ‘substance,’ Aquinas is deliberately drawing our attention to the fact that persons not only underlie all other modes of being as substances, but he is further clarifying that persons are the kind of thing that have being in themselves, something latent in but not yet clarified by the term ‘substance.’
Whereas ‘substance’ focuses our attention on the person as the kind of being that underlies all other modes of being, making these modes of being secondary and accidental, ‘subsistence’ focuses our attention on the self-dependent mode of being of individual substances—and thus on the very existence of persons, on their concrete actuality. To state this simply, Aquinas is revealing that persons possess being in a primary way, and are thus a preeminent kind of being; and to state this still more simply, he is revealing that all actual personal individuals matter. Indeed, this is the foundational dignity of being a personal substance.
This fact—the existential actuality of persons—is then always and everywhere important. Even if the particular individual is underdeveloped, as we find in the human fetus, and even if the particular individual suffers a personally debilitating disease, such as dementia in its various forms, the very fact of the existence of the person demands a response appropriate to the reality; and that is a personal response to their substantial dignity. Now, once we have located this grounding dignity of persons in their being as subsistent substances, we must extend our appreciation of this basic dignity by considering the nature of the personal substance, for we have not yet seen why the tradition holds the person in particular to be more significant than all other kinds of substances. This further grounding of personal dignity—which we will come to understand as the ultimate basis of the dignity of persons—is found in another term of the Boëthian definition, namely, in the rationality of the personal nature.
Since the rational nature capacitates persons to attain intellectual union with reality, inasmuch as reason is an open potency to receive the formal intelligibility of all kinds of things, the personal substance has a dignity far superior to all other subsistent substances. The basis of this qualitative intensification of dignity is located in persons’ ability to attain truth. As originally detailed by Aristotle, knowledge involves the intellectual union of knower and known, when the knowing subject apprehends the intelligible form of the then known object. On the basis of this basic form of intellectual union, the knower can then formulate concepts, propositions, and arguments for himself, according to which understanding is achieved in varying degrees. In this way, the personal subject reaches out and grasps reality and thereby attains to the truth of things.
On the basis of this ability to reach for and attain to truth, the person has a corresponding capacity to navigate the world with freedom. It is impossible to consider freedom without considering truth, and it is impossible to recognize the significance of truth without seeing its intimate relation to freedom. Indeed, truth is a necessary condition of the possibility of the exercise of freedom, since acting with freedom is possible only when what lies before us can be seen, and only when what can be chosen on the basis of this seeing is also seen as a possibility able to be realized. This ‘I can’ (with its correlative, ‘I can refrain’) is the basis of freedom, and this ‘ I can’ is conceivable only together with truth: against the backdrop of truth, as a realization of truth, while truth entirely permeates its exercise. Hence, we see that truth sets us free.
Now, it is with this possibility for the realization of free action that we come to the very heart (literally!) of the significance of persons, for it is precisely here that find the nexus of everything personal. Since our actions are our own, and since it is through these same actions that we manifest our being as the subsistent substances we are, freedom is the focal point of the dignity of persons. And this is why in my opening essay I quoted St. Thomas insight about the significance of substances bearing a rational nature, when he says, ‘in a more special and perfect way, the particular and individual is found among rational substances [that is, persons], who have dominion over their own actions’ (ST I, 29.3 co.). This dominion persons have over their own actions makes persons significant precisely as subsistent individuals, that is, as actually existent, concrete singulars. This is at the heart of why persons are beings bearing preeminent dignity, and this is exactly why the term ‘person’ was crafted slowly through human history—up until the contemporary age and the dawn of personalism as a philosophical movement.
Simply stated, we needed a special term to identify ‘that which is most perfect in all nature’ (ST I, 29.3 co.).
In the next essay, we will consider the significance of the person as an individual, for, as we have just seen, it is because of the just detailed singularity of action that the significance of the individual is foregrounded in an absolute sense. In this further essay, I will draw together the above detailed substantiality of the person and the earlier detailed subjectivity of the person, for both will be significant toward appropriately understand the meaning of being a person as an individual. And there we will see that everything I have detailed so far when considering the significance of persons in terms of their subjectivity and substantiality is finally for the sake of understanding persons as individuals.
* Boëthius’ definition is formulated with a subtle difference to its usual repetition in later thinkers; he actually uses ‘rationabilis, rationable’ instead of ‘rationalis, rational,’ which is obviously significant for our consideration of the dignity of persons who cannot (for whatever reason) exercise their rationality (whether in thought or in free choice), and precisely as subsistent substances.
