On The Metaphysics Of The Human Person

Apr 26, 2023

Dear Souls and Hearts Members,

I am excited and honored to provide a forum for Catholic philosopher Monty De La Torre to share with us some metaphysical foundations to better understand who we are as human persons. We need to understand who we are in order to know how to change, how to embrace a wholesome human formation that facilitates us following the two great commandments with their three loves: loving God, neighbor, and ourselves in an ordered way.

If you don’t understand the philosophical concepts in this article, no worries. At Souls and Hearts, we are committed to bringing you the best of human formation resources grounded in an authentic, Catholic understanding of the human person, and this article is an important first step to helping us think about systems, multiplicity, and parts within the tradition of our Church, so that we can benefit from the insights of the art and science of modern psychotherapies while remaining firmly grounded in our Faith. We are here to help you, and we provide these kinds of articles to show that we are reflecting deeply about how to ground human formation in a Catholic anthropology.

To that end, and without further delay, I present to you this guest article:



On The Metaphysics Of The Human Person by Monty de la Torre, Ph.D.

The purpose of this article is to help us begin to understand the metaphysics of human formation from an Aristotelian-Thomistic point of view, i.e., from the philosophy of St. Thomas Aquinas (1225-1274 A.D.) who baptized the work of Aristotle (384-322 B.C.).

However, before discussing the metaphysics of human formation, we need to have a sound understanding of the human person. Why?

Because human formation is contingent upon human nature. We need to know what a person is before we can determine how and what a person needs to be formed, i.e., a life formed or directed toward a proper love of God, self, and others.

To answer the question of human nature requires knowledge of metaphysics.

Definition of metaphysics

You may be asking, “What is metaphysics?” and “Why metaphysics?”

To answer these questions, we need to define the term. The following is a definition given in Bernard Wuellner’s Dictionary of Scholastic Philosophy:

Metaphysics: the science of the absolutely first principles of being: the science of being as such. It is also called ontology, first philosophy, philosophy of being, wisdom. [2012, p. 76]

In short, metaphysics is the study of the fundamental principles responsible for holding reality together. These principles are self-evident and necessarily exist independent of the mind. (For more on metaphysics and first principles, see here and videos 2-4).

We cannot deny these principles without devastating consequences. If we begin with correct first principles, then our conclusions will land on safer ground. So, we need correct first principles about human nature before we can arrive at correct human formation. If we fail to understand what a person is at the metaphysical level, then there is a strong chance that we will fail in answering the question of human formation. As St. Thomas noted, “A small mistake in the beginning is a big one in the end…”

Metaphysics is meant to provide us with the non-negotiable principles to answer human formation question as correctly and precisely as possible. This introduction to key metaphysical principles will provide you with a clearer idea of what a person is. What follows is going to be somewhat abstract and technical, but it will pay dividends once the discussion turns to the person.

Potency and act

In his 2009 book Aquinas: A Beginners Guide, the Catholic philosopher Edward Feser provides us with a helpful introduction to some key concepts that must be kept in mind as we begin our investigation of human nature and human formation. In the ancient world, there was a debate that took place between two schools of thought. On the one hand, the ancient philosopher Parmenides (c. 515-450 B.C.) believed that change was an illusion or impossible. You read that correctly. Change is not taking place according to Parmenides. Feser illustrates Parmenides’ argument with the following example:

Consider once again your coffee, which starts out hot and after sitting on the desk for a while grows cold. You might say that the coldness of the coffee, which does not exist while the coffee is hot, comes into existence. But now we have a problem, says Parmenides. For if the coldness of the coffee was initially nonexistent, then at that point it was nothing; and when it later comes into existence, it is then something. But something can’t come from nothing. So, the coldness of the coffee cannot come into existence, and thus, the coffee cannot grow cold. Something similar could be said for any purported case of change – all of them would have to involve something coming from nothing, which is impossible. Hence, concludes Parmenides, change cannot ever really occur.

Parmenides believes that all of reality falls into one of two categories, either being or non-being. Given his argument, Parmenides concludes that all of reality simply is, being or one. There is only one thing that exists: BEING itself!

On the other hand, his contemporary Heraclitus (c. 535-475 B.C.) believed that all things were in a state of flux or change. He is famously known (at least in the minds of philosophers) for the notion that you cannot step into the same river twice because new water is constantly flowing. In other words, there is no static being or permanence, but constant change and impermanence.

Aristotle thought otherwise. He understood Parmenides and Heraclitus as setting up false dichotomies. Aristotle believed that Parmenides and Heraclitus failed to make the distinction between those things which are in act or actuality from those that are in potency or potentiality. To borrow an example from Feser, a rubber ball is potentially many things. It can be smashed into pieces or cut in half or melted into a puddle of goo. Then there are the ways that it actually is, “solid, round, red, and bouncy.” (2009, pg.10).

Act/Actuality: something in existence, a thing that currently exists.

Potency/Potentiality: the way something could be. (Potencies can also be referred to as powers. So, we have a multitude of potencies or powers: the potency/power to jump, cry, sweat, talk to our parts, etc.).

In response to Parmenides and Heraclitus, Aristotle and Aquinas would argue that the potencies of the rubber ball exist in the ball. Change occurs when potencies transition from potency to act. However, for that transition to take place, requires some outside agent (e.g., flame and heat) to melt the rubber ball. What ensues is a transition from potency to act (potential gooeyness to actual gooeyness). This becomes the fundamental explanation for how any kind of change or motion (understood to mean any kind of change whatsoever) takes place.

Change/Motion: is the transition from potency to act.

Potencies are limited by a thing’s essence or nature

Some important consequences ensue from these basic distinctions. First, a thing’s potencies are rooted in that thing’s nature or essence (more on essence later). In other words, the potencies that a thing has are rooted in what that thing is. Thus, a rubber ball can be melted into a puddle of goo, but it does not have the potency to turn into gold as some alchemists might claim. It is simply not in the nature of rubber to be able to turn into gold.

Potencies do not actualize themselves

Second, potencies do not actualize themselves. A rubber ball can only be melted into a puddle of goo by some external agent, like flame and heat, which makes the ball melt. Potencies are not actual until they transition from potency to act (i.e., a transition from existence as a potency to existence as something actual).

Act is metaphysically prior to potency

Third, act is metaphysically prior to potency. A potency can only exist in something that is actual. For example, the potency for jumping can only exist in something that exists because existing things jump, not potentially existing things. Hence all potencies exist in something that is actual.

One key takeaway from this concerning Internal Family Systems is this: we have the potency for having parts and communicating with those parts because those potencies/powers are grounded in our essence, i.e., human nature. If we did not possess these potencies, then we would not, in principle, have parts in the sense that Internal Family Systems proposes.


St. Thomas believed that material objects are composed of two principles: matter and form, which came to the be known as the doctrine of hylemorphism – derived from the Greek words hyle ( for “matter”) and morphe ( for “form”).

All material objects are compounds of matter and form

Going back to the rubber ball. We see that the ball is made of rubber. We can think of this as the matter of the rubber ball. The ball also has the shape of a ball; this is the form (i.e., what gives the object its identity).

Now, try to think of one (matter) without the other (form). It’s not possible. Only in the abstract can you separate the form from matter. Matter and form cannot be separated. (There are some important caveats to this, but they are not important for present purposes). Therefore, all material objects must be composed of both matter and form.]

Substantial form and accidental form

Form can come in one of two ways: substantial form and accidental form.

Substantial form is that which makes something exist as what it is. Substantial form is essential to the thing being the thing it is. Substantial form determines what a thing is; that thing is what it is because of substantial form.

Accidental form is what makes something exist, but in a qualified way; an accidental change modifies the thing in some way without changing what that thing actually is.

When a material object changes, it loses one form and gains another, going from potency to act.

Some of these changes are accidental and some changes are substantial. For example, if you were to whittle a few shavings off a piece of wood, the wood would be different – it is changed, but still recognizable as wood. This would be an accidental change -- the whittled wood is still wood. However, if you burned the wood, eventually the wood undergoes a substantial change, and is no longer a piece of wood. It has changed substantially into smoke and ash. For a more complete discussion of matter and form, check out this article.

From a Catholic perspective, when we understand the internal multiplicity of a person (as Internal Family Systems and other models of the human person posit), our parts (or subpersonalities) can only have accidental form and not substantial form.

Why? Because if parts had substantial form, then we must explain how a multitude of actual separate persons – each with a body, soul, mind, etc. -- live within us!

The Four Causes

Another Aristotelian-Thomistic doctrine is the four causes. The four causes are the four principles that give a general metaphysical account of the things that exist, either materially or immaterially. These four causes are the material cause; the formal cause; the efficient cause; and the final cause.

The material cause is the matter of an object as discussed above.

The formal cause is the substantial form or essence of a thing. This cause is responsible for the “whatness” of a thing, or its principle of identity. In other words, the formal cause makes a thing the kind of thing it is. For example, gold is gold because it has the essence of gold and not silver.

The efficient cause is that which causes something to go from potency to act. For example, if Tom pushes Bob, then Tom is the efficient cause of Bob falling to the ground. The final cause is the purpose(s) of a thing, or all the potencies/powers that a thing possesses are the final cause(s) of a thing. In other words, what a thing can do or what can be done to it constitutes its final cause(s).

These are some of the basic metaphysical assumptions that will be at play as we turn to discuss human nature.

The soul defined

The soul is the substantial form of the body (i.e., think in hylemorphic terms: matter = body; form = soul). Soul is a term used to delineate a specific kind of substantial form, i.e., the substantial form that makes something to be alive or animate instead of inanimate. In other words, animate things have substantial forms, and we call those forms souls. Inanimate things also have substantial forms; however, we do not call those forms a soul. (For some helpful videos on this topic, see 16-20).

Soul: the substantial form/essence that makes something to be animate. Thus, all living things (plants, animals, human beings) have souls.

Piecing this together with us specifically in mind: a human person is a hylemorphic substance because it is composed of matter and form. Specifically, a person has a soul because he is a living substance and not an inanimate one. A person has a material cause (his body) and a formal cause (his substantial form/essence). A person also has an efficient cause, namely, his parents. A person also has a final cause(s), i.e., all the potencies or powers that a person can have.

Going further, what differentiates humans from other animals are two specific powers or potencies that no other animal has, namely, the powers of intellect and will. These powers, as Feser notes, have their own final cause:

The natural end or final cause of the intellect, with its capacity to grasp abstract concepts and to reason on the basis of them, is to attain truth… The natural end of the will is to choose those courses of action which best accord with the truth as it is discovered by the intellect, and in particular in accordance with the truth about human nature. [2009, pp. 142-143].

Moreover, since God is the highest truth,

…the highest fulfillment of the human intellect is to know God… and since the will’s natural end is to choose in a way that facilitates the realization of our natural ends as human beings, the highest fulfillment of free choice is to live in a way that facilitates the knowing of God. [2009, p. 143].

It is these two powers specifically that make us, according to St. Thomas, in the image and likeness of God.

Fragmentation to reorientation for our parts

These last few points are crucial in considering human formation. I contend that the fragmentation of our parts requires us to reorient them through unblending and unburdening so that those unintegrated parts within, allow us to pursue our natural ends (i.e., final causes) with as much freedom and integration as possible. This is the goal of Internal Family Systems. Metaphysics gives us the blueprint for understanding how to ground IFS in an authentically Catholic anthropology, rather than rely on the subjective phenomenology of its founder, Richard Schwartz.

Much more could be said about the powers of intellect and will, and the implications of metaphysics for understanding IFS (e.g., how parts interplay with memory and imagination), but for the sake of time and space, I will leave it there for now. I hope this will open a fruitful conversation about the role of metaphysics in our internal work, informed by IFS and other parts-based approaches.


Feser, Edward. 2009. Aquinas: A Beginners Guide. Oneworld.

Feser, Edward. 2017. Five Proofs Of The Existence Of God. Ignatius.



Thank you, Dr. De La Torre, for your insights.

Demonstration of unburdening: relieving parts from their sexual burdens

I am excited to share with you a 79-minute session where Drew Boa and I unburdened three of his parts on his podcast Husband Material, in his episode titled Unburdening Sexual Arousal. Drew and his podcast are all about helping men outgrow pornography and become better equipped to be solid Christian husbands and fathers. If you are interested in the unburdening process, check this example out.

Be With the Word for the Fourth Sunday of Easter

Join Dr. Gerry and me for our Be With the Word episode titled Being Docile Through Criticism.  When Jesus, the Good Shepherd, calls us to be His sheep, He is calling us to be docile. This often means listening to Him through others, being humble, and being open to others’ concerns, and even criticisms, about us.  Dr. Gerry and I share the Mass readings out loud here.

Ask Marion and me anything about anger on Interior Integration for Catholics

In episode 113, Resilient Catholic Community Lead Navigator Marion Moreland and I will host a live show answering any questions you have about anger. We will record on Tuesday, May 9 from 7:00 PM to 8:15 PM Eastern Time -- register to join us for free with this link.

The Resilient Catholics Community and human formation

Our outreach, Souls and Hearts, brings you the best of human formation resources, grounded in a Catholic understanding of the human person. The Vatican II document, Gaudium et Spes (translated as The Pastoral Constitution of the Church in the Modern World), reads: In pastoral care, sufficient use must be made not only of theological principles, but also of the findings of the secular sciences, especially of psychology and sociology, so that the faithful may be brought to a more adequate and mature life of faith. That’s what we do in bringing you the best of the science and art of psychology and other disciplines to inform human formation.

Within Souls and Hearts, I founded the Resilient Catholics Community (the RCC) for Catholics who are committed to going to the deepest natural levels within themselves to working through unmet attachment and integrity needs, learning the three loves our Lord commands in the two great commandments: to love of God, one’s neighbor, and one’s own self.  

The RCC provides a very structured year-long human formation program with many resources and the support of other Catholics in small companies, all making a pilgrimage toward better human formation with individualized human formation plans.  The camaraderie and connection in the companies and with your companions are essential on the pilgrimage.  

If these weekly reflections and the Interior Integration for Catholics podcast resonate with you, learn more about the RCC and sign up for our interest list on our landing page; the RCC reopens to accept new applicants again from June 1 to June 30, 2023. 

Warm regards in the Risen Christ and His Mother,

Dr. Peter

P.S. If you want a basic, accessible introduction to core concepts of Thomistic approaches, Dr. De La Torre recommends this article and this video playlist.

P.P.S. Please pray for us at Souls and Hearts. Prayer is our fuel, it animates all the good that we do, and prayer is the greatest gift you can give us. Know that we are praying for you as well.

  Social Media Sharing

50% Complete

Be with the Word.

60 second summaries each week to help
you get the most out of this Advent.