My fellow humans, what exactly are we? To answer this question, scholars throughout history have advanced three different philosophies: materialism, dualism and hylomorphism. Each system's respective theory of man differs vastly from that of its competitors. And these differences are far from merely academic — rather, they are of serious real-world consequence.
Each of the foregoing philosophies has, at one time or another, enjoyed widespread popularity. Nevertheless, only one is consonant with Christian anthropology; only one provides the necessary foundation for human flourishing; only one is officially adopted by the Catholic Church.
Let's take a quick look at the three major ontological theories of man, one at a time.
The materialist view of the human being is the simplest of the three. It alleges that humans are walking, talking animals — physiological bodies that molecules randomly and temporarily form before becoming part of the earth again. Man is seen as having no soul, no spiritual component, nothing immaterial that transcends the biologically determined instincts that would allow him to seek the truth and freely choose the good.
Fittingly, virtually all materialists are atheists. The worldview born of this identity holds there is no objective meaning or purpose to life and that morality is purely subjective. Attitudes and lifestyles of hedonism, cynicism and nihilism are its logical progeny.
While some ancient Greeks, including Epicurus and the atomists, held a form of materialism, it reappeared in contemporary times through modern philosophy. Thomas Hobbes was among the philosophers who reintroduced materialism to the Western world. The work of Darwin, Marx and Freud blazed a trail for the materialist paradigm to permeate science, politics and psychology, respectively.
It's natural that the materialist view of man would spawn a pleasure-based ethic. And that's exactly what happened. Jeremy Bentham and John Stuart Mill introduced utilitarianism to modernity in the 18th century, challenging natural law theory for cultural dominance in the West.
The second philosophy of the human person, known as dualism, was popular in antiquity, and boasted champions such as Socrates and Plato. Dualism was reintroduced, however, in its modern form by René Descartes. Descartes' famous line "I think, therefore I am" was the product of the famous thinker's doubts about the trustworthiness of his senses and the very existence of material beings (including his own body). In short, Cartesian dualism is the belief that we human beings are immaterial minds inhabiting physical bodies that are non-essential to our being.
Modern dualism may be a step up from the ancient dualism that saw the body as a prison for the soul that keeps it from being free to live in the immaterial world of ideals. Nonetheless, existing essentially as a thinking mind has repercussions. The dualist sees the body not as an integral component of his person, but as an object, a thing to manipulate, an instrument. Such a fundamental error about the nature of man has serious moral repercussions.
This depersonalization of the body renders natural law morality unintelligible. When physiology is divorced from one's being, as in dualism, bodily acts are stripped of their moral value. "Adult consent" becomes the ethical fulcrum, rather than "do good and avoid evil." Further, the notion of "transgenderism" (i.e., the idea that the body can be different than the person inside) would have no plausible mechanism if not for anthropological dualism.
Most Asians throughout history have identified with some form of dualism. Hindus, Buddhists and members of various ancestor-worship societies believe in the transmigration of souls, from one body to another. This notion of reincarnation, widely held in the Far East, fits only with a dualist model of man.
According to the materialist philosophy, we are only bodies; and according to the dualist philosophy, we are minds accidentally attached to temporary bodies. The third model of what it means to be human — hylomorphism — is, in a certain sense, a middle ground between both.
The term "hylomorphism" comes from the splicing of the Greek words hylē ("matter") and morphē ("form"). Hence, the hylomorphic paradigm is that the human being is one substance (not two, as in dualism) that is a composite of matter and form. And since the soul is the form of the body, the human being is a composite of a physical body and a spiritual soul. Aristotle first articulated this concept in pre-Christian Greece, and the Angelic Doctor, Thomas Aquinas, perfected it in the Scholastic age.
The Church has adopted hylomorphism as its official understanding of the human person, the image of God on earth. Indeed, the 14th-century Council of Vienne confirmed,
Furthermore, with the approval of the Holy Council, We reject as erroneous and contrary to the truth of the Catholic faith any doctrine or opinion that rashly asserts that the substance of the rational and intellectual soul is not truly and of itself the form of the human body or that calls this into doubt. In order that the truth of the pure Faith may be known to all and the path to error barred, We define that, from now on, whoever presumes to assert, defend or obstinately hold that the rational and intellectual soul is not of itself and essentially the form of the human body is to be censured as heretic (quoted in Heinrich Denzinger and Peter Hunermann, Enchiridion Symbolorum, 43rd edition [San Francisco: Ignatius Press, 2012], §902).
Hylomorphism contradicts the common Platonic view of death (which many Christians believe out of ignorance) that the soul is freed from the body and lives forever as a pure spirit. This is dualism, not hylomorphism, and it is not Catholic teaching. Contrary to dualist thought, we are not pure spirits like angels; and contrary to materialist thought, we are not pure bodies like animals. We are body–soul composites, uniting in our being Heaven and earth, the spiritual and the physical.
Hylomorphism also renders reincarnation and so-called transgenderism impossible, because the philosophy holds the body to be the physical manifestation of the soul, and so, accordingly, the two can never be substantially differentiated.
On the surface, the reality of death seems to jibe most naturally with dualist and materialist philosophies of man. Christian hylomorphism, on the other hand, makes two claims that seem to be contradictory: (1) body and soul are inseparable as one substance, and (2) humans live on after bodily death. This quandary, however, is solved by the Resurrection.
The Catholic Church teaches that the separation of soul and body at death was not part of God's original plan for humanity. Instead, human death entered the world through the sin of our first parents. Adam rejected supernatural grace and the preternatural gifts God gave him, including immortality, by consuming the forbidden fruit. Yet, since the soul is spiritual and substantial by nature, it doesn't break down or decompose as do physical bodies. It naturally survives bodily death, albeit as an incomplete human being. After its particular judgment, the spiritual soul anticipates the resurrection of the body and General Judgment that occurs at the end of history.
One cannot forget the central teaching of Christianity on the Resurrection: On Easter, Jesus rose bodily, not just spiritually. And by His grace, He invites us to follow Him through death to bodily resurrection. As Scripture further indicates, all creation, not just human bodies, will be transformed in some fashion:
Creation itself will be set free from its bondage to decay and obtain the glorious liberty of the children of God. We know that the whole creation has been groaning in travail together until now; and not only the creation, but we ourselves, who have the first fruits of the Spirit, groan inwardly as we wait for adoption as sons, the redemption of our bodies (Romans 8:21–23).
So while it is true that "the souls of the righteous are in the hand of God, and no torment will ever touch them" (Wisdom 3:1), it is also true that "sin came into the world through one man and death through sin, and so death spread to all men because all men sinned" (Romans 5:12). This deadly consequence of sin is conquered in the Resurrection. Just as in Adam all die, so too in Christ shall all be brought to life, but each one in proper order: Christ the first fruits; then, at His coming, those who belong to Christ (1 Corinthians 15:22–23).
The Catechism of the Catholic Church puts it this way:
Death entered the world on account of man's sin. Even though man's nature is mortal, God had destined him not to die. Death was therefore contrary to the plans of God the Creator and entered the world as a consequence of sin. Bodily death, from which man would have been immune had he not sinned is thus the last enemy of man left to be conquered (¶1008, internal quotation marks omitted).
Sin has always led humanity to vacillate between two extremes without permanently landing on the truth. We post-Eden humans tend to think of ourselves as either angels-in-waiting or smart animals. We fluctuate between overemphasizing our spiritual nature and glorifying our bodily nature. This polarity leads to one of two extreme results — the abnegation of physical pleasure or the glorification of it.
The materialist view of man is a prime example of overemphasizing the material body, while the dualist model is a choice example of overemphasizing the spiritual soul. The balanced understanding of Christian hylomorphism saves us from these errors and enables us to know ourselves as spiritual earth-creatures made in God's image, tarnished by sin but destined for glory.