The Immortality of the Soul According to Thomas Aquinas

This article systematically examines the question of the human soul’s immortality—or incorruptibility—in the writings of Thomas Aquinas. The study traces Aquinas’s three-stage argumentation across his academic career, distinguishing his approach from those of Plato, Aristotle, and later thinkers. The first stage highlights the immateriality of human intellection, deduced empirically from the soul’s capacity to know all corporeal forms and to abstract universals. Moving to the metaphysical plane, as a second stage, the analysis underscores the principle that a proper immaterial operation necessitates a corresponding immaterial esse (act of being); this distinct existence, Aquinas contends, is grounded in divine creation rather than natural pre-existence or an emanation from a universal soul. Finally, the paper details how Aquinas resolves the tension of the human psycho-somatic unity. The article clarifies that as a subsistent immaterial form, the soul is incorruptible per se, even upon the body’s demise. Furthermore, the article briefly assesses various historical and practical objections regarding the separated soul’s impoverished activity and individuation without matter. Ultimately, the text maintains that Aquinas’s nuanced philosophical defense takes the reality of death seriously and deliberately avoids Platonic dualism. This approach, it posits, serves as a reasoned “preamble to hope” that rationally complements the Christian doctrine of bodily resurrection rather than substituting it.