Human Dignity and Soul
The atheist, materialist, and even some scientific interpretations of the "soul" differ sharply from that which the Catholic Church teaches. In the popular or materialist view, the soul is often portrayed as a "ghost in a machine," a Gnostic concept that posits the body as merely a vessel or the soul as merely a part of either the brain or mind. This misunderstanding becomes a strawman for atheists and materialists to refute, for it seems to conflict with empirical science. However, the Catholic understanding, rooted in Aristotle and perfected by St. Thomas Aquinas, presents no true quarrel with science. The Church teaches that the soul is the form of the body, constituting with it a single human nature (cf. CCC 365, 382). As Aquinas beautifully articulates, "the soul is not in the body as contained by it, but rather contains the body" (Summa Theologiae I, q. 76, a. 8).
The soul, in Catholic doctrine, is the spiritual principle of a human being, intimately connected to the body and creating an indivisible unity (CCC 364). It is the innermost aspect of the person, bearing the imprint of God's image, and it is immortal, directly created by God (CCC 363, 366). Aristotle hints at this essential unity when he considers whether the soul may be to the body as a sailor is to a ship. Yet Aristotle concludes—and Aquinas confirms—that being alive cannot belong to a body as such; otherwise, all bodies would be alive. “Suppose that what is literally an 'organ', like an axe, were a natural body, its 'essential whatness', would have been its essence, and so its soul; if this disappeared from it, it would have ceased to be an axe, except in name.”[1]
Approaching the matter philosophically, especially through causality, reveals the strength of Aristotle's and Aquinas’ arguments. If the body were capable of self-animation, it would have to be its own cause. Yet, causality and contingency teach otherwise: the body, being material, is contingent, and thus cannot be its own cause. Only God, whose essence is existence (cf. Exodus 3:14; Summa Theologiae I, q. 3, a. 4), can claim such necessary existence. Consequently, if the soul were merely bodily, death would be impossible, for the body would eternally self-sustain. Yet death is real. Therefore, the soul must transcend mere materiality.
Moreover, human dignity itself testifies to this reality. Even when the body deteriorates through illness or age, a person's dignity remains intact. The soul’s spiritual nature, being the "form" and not merely the "content" of the body, means that man remains a person even after bodily death. As Christ teaches, "For in the resurrection they neither marry nor are given in marriage, but are like angels in heaven" (Matthew 22:30), indicating the soul’s continued existence beyond bodily death.
The union of body and soul constitutes one human nature, not two. The soul is the life principle, animating the material body and rendering it human (CCC 382). Through it, man possesses intellect and will—powers directed toward truth and goodness—thus exceeding purely biological processes. A cow’s soul, being mortal and material, ceases at death, whereas man’s soul, spiritual and eternal, endures. This distinction is not minor but critical: it separates humanity from the animals and anchors Christian anthropology against the flattening effects of materialism.
In modern times, science may measure brain activity and physiological responses but cannot detect the soul. Yet, this is expected. The soul, being immaterial, cannot be observed by empirical means. Faith, supported by reason, reveals its presence. Practically, we sense this in our existential experiences: when confronted by the death of a loved one, it is immediately evident that the person is not merely their body. Our longing for eternal meaning, our capacity to contemplate universals, and our irreducible dignity all point to our spiritual nature.
In sum, the arguments of Aristotle and Aquinas remain compelling. Life does not belong to the body by itself. The soul is the form of the body, created by God, immortal, and spiritual. Denying this truth leads not only to philosophical errors but to the dehumanization of the person. Affirming it grounds human dignity, moral responsibility, and the hope of eternal life in God. However, in dialogue about the soul, if one is a materialist, then we should not start with a singular tenet of belief in the immaterial. Otherwise, our dialogue ends up being circular: one presents an argument for a particular immaterial reality, the interlocutor replies with skepticism and not necessarily malicious but no less real strawman, and an appeal back to disbelief in the immaterial, one provides another argument, and then the interlocutor does the same. The soul cannot be reduced to a part of that which it is the form of without it being erroneous, and to try to explain the function of particular parts of the body as if the lack of optical need to discuss soul evanesces is not a philosophically nuanced view but only a specialized scientific observation with an atheist interpretation.
View Bishop Barron on the Subject
FN:
- Aristotle, "On the Soul," translated by J. A. Smith, at The Internet Classics Archive (350 AD) at http://classics.mit.edu/, Book II, Part 1.
