Augustine v. Aquinas

Saint Augustine and Aquinas are both famously known for their philosophical and theological explorations, with Augustine writing in the late fourth to early fifth century and Aquinas in the thirteenth. While they are both known for attempting to reconcile ancient philosophy with Christianity, they went about this task in different ways. Augustine is known for taking a Platonic route, whereas Aquinas was much more Aristotelian.  The two both explored the faith and reason dichotomy, the nature of the soul, and knowledge.


Section I: Faith and Reason           

            With the Middle Ages came the rebirth of the idea that religious belief did not only stem from faith, but also from reason. This idea was no stranger to ancient thinkers, but it reappeared with Augustine. To be clear on what the two are; faith is seen by the two philosophers as a trust in scripture and one’s own personal belief that God exists. Reason would be a more rational approach to the proof of God, with appeal to evidence and logic. St. Augustine believed that faith and reason had an interdependent relationship in understanding God, but also that faith would always be the truest way to God. Additionally, both faith and reason were only accessible due to divine grace of God. As stated before, Augustine was very much a Neo-Platonist. He believed because the Platonists studied the eternal and unchanging that these ideas were beneficial to understanding and clarifying the Christian faith.

            While Augustine believed that using reason (which for him included logic, history, and natural sciences) was beneficial to illuminating the Christian faith, he also believed that using these avenues in order to do so was only necessary if one was not a Christian. He believed that a Christian did not have to take such recourse to philosophy (reason) because he felt faith was superior to reason in terms of belief in God. He believed an intellectual investigation of faith should be understood as fides quaerens intellectum, or faith seeking understanding. Augustine held that faith was to come first, especially if reason should contradict scripture. In such a case, he regarded the Church, rather than the individual believer, as having the final authority to say what “reason” could be used in one’s personal inquiry into their faith.

            Saint Thomas Aquinas took a fairly different stance on the faith and reason dichotomy. He did not make as clear a distinction between faith and reason, as Augustine did, but did believe that all creation and truth is emanated from God. Aquinas did not believe that reason and faith conflicted, though there are truths that reason cannot attain that faith can. Aquinas called this idea a “two fold truth”. He held that something can be true of faith, false or inconclusive in philosophy, but never the other way around. This idea supports the idea that while reason can lead one to a greater understanding of the world, it cannot lead to attainment of the higher truths that faith can.

            Aquinas believed that faith and reason, are essential and not contradictory, in fact, knowledge is essential in the act of faith. He asserts that faith is the intellectual act, and its object is truth. Thus, any truth will necessarily lead to faith. Aquinas claimed that while people cannot comprehend God as an object, the intellect can grasp his existence indirectly, and this grasp comes through reason.

            Aquinas somewhat agrees with Augustine on the question of contradiction between reason and scripture. Aquinas maintained that while there may be no evidence of something from sensational experience, which he took to be how we perceive the world, we must trust in “articles of faith” which he defines as divine testimony, or scripture. For example, though there is no sensational evidence for the world not being eternal, Aquinas believed that the “article of faith” (and through his logical argument) that we must accept this as true.


Section II: The Soul

            Over the course of his writings, Augustine made changes to his views on the soul. In his earlier writings he took on a very Platonic definition in that the human soul is a substance that is capable of reason and is made to rule the human body. This soul is separate from the body and is merely using it. This view changed a bit later in his writings, when he places more importance on the unity of the body and soul. While Augustine believes that a human being certainly is a rational soul that controls the human body, he also says that the “soul which has a body does not make two persons, but one human being” (Johannis evangelium tractatus). However, he does remain true to his Platonic ideals by placing the soul in the Plato’s real of understanding or forms, where abstract ideas reside.  Augustine believed the soul was a “rider” of the body, which made the clear distinction of material and immaterial substances; body and soul.

            Christianity teaches there is life after death. Augustine was committed to this view as he took scripture to be the direct word of God. He believed that “after the Fall [original sin] this [the afterlife] was not available to us. In redeeming us from our original sin by his death and resurrection from death, Jesus redeemed us from original sin, restored our relationship with God, and made it possible for us once again to live eternally with God in the life hereafter.” (Wall) Augustine believed that the soul went on to live in kingdom of heaven, and entrance to the kingdom was “available to all who love God and their neighbor.” (Wall)

            Augustine has two arguments, derived from Platonic reasoning, as to why the soul is immortal. His first argument pertains to science. Augustine argues that if science exists anywhere, it exists in the living. Also, since science is eternal, that in which it lives must be eternal too. He further argues that humans are the only living beings who possess a rational soul, and cannot reason without science. Therefore, science must exist in human soul; thereby concluding the human soul is immortal. Augustine’s second argument for the immortality of the soul is that the “mind is life, and thus it cannot lack itself.” He explains this further by asserting that when a living thing dies, we do not think of the physical matter as being dead, but as it being abandoned by life. Augustine believed the mind (soul) to be source of life for a body, and something cannot lack itself; the soul cannot lack itself, thus it cannot die.  (De Immortalitate Animae)

            Thomas Aquinas had similar views in that there is indeed life after death, and that the soul is separable from the body, but went about supporting these claims in a different way than Augustine. First, we will explore Aquinas’ view of the nature of the soul. Aquinas took a very Aristotelian viewpoint this topic in sticking with his idea of “causes”.  Aristotle asserted that there were “four causes”, material, formal, efficient, and final. Aquinas agreed with Aristotle in believing that the soul was the “formal” cause of the body. This made Aquinas’ view on the soul compatible with Aristotle’s because it set up his argument to suggest that the soul could be separated by abstraction from the body, which will be explained further in this section.

            One of Aquinas’ weaker arguments for life after death is that of desire. This argument states that no desire goes in vain under God. By this statement, Aquinas infers that the desire to live after death of the body would not go in vain either. A stronger argument for the possibility of the immortal soul is concept formation. Aquinas asserted that because people are capable of thinking of abstract ideas apart from material substances, for example, thinking of a triangle without seeing one, that this is evidence of the soul being able to exist without attachment to material substances also.

            Perhaps the strongest argument Aquinas made for the immortality of the soul is the justification of separation of the body and soul.  As stated before, Aquinas was very influenced by Aristotle, and that is no different when he accounts for the soul. To understand Aquinas’ views on the soul we must first clarify between “subsistent” and “substance”. A subsistent for Aquinas is something that is able to exist on its own, not in another. A substance is something that “is subsistent and complete in nature – a nature being an intrinsic principle of movement and change in the subject.” (SEP) Thus, both the human body and soul are both capable of existing on their own, but they are only substances when joined together in their complete nature. By this Aquinas also is accepting that the soul is the form of the body, which is yet another Aristotelian view he adopted in order to argue for the immortality of the soul.

            Aquinas argues that because the soul is a spiritual entity, it does not depend on matter and can exist separately from the body. Aquinas believes that the human existence in its perfect form is in the dual nature of soul and body, which relates directly to his belief in resurrection in the afterlife. Aquinas appears to have three arguments for the immortality of the soul.


Secion III: Knowledge

            Augustine drew much of his theory of knowledge from Plato, especially in his desire for certain knowledge rather than changing or impermanent knowledge. Contrary to Aquinas, Augustine was not an empiricist. Augustine believed “that the truth is found from within, through a process of illumination, and not by observing the world of nature.  It had been Plato’s view that such knowledge arose from a process of remembering the Forms from a past existence, which was made possible by the Good illuminating the mind to remember. Augustine builds upon these Platonic ideas but alters them dramatically” (Wall).  Augustine agreed with Plato in the sense that true knowledge came from within, but Plato believed it came from “remember”, whereas Augustine believed it came from “illumination”.

            Augustine believed that these certainties could not be taught, just as Plato thought, but Augustine thought these ideas came from illumination through Christ, the divine teacher. This is why Augustine believed reason to be divine, “because understanding is made possible by the “light of Christ”, and thus is a gift from God” (Wall).  Augustine believed that in any instance an idea is formed in the rational human soul, synonymous with mind in most cases, it is because Christ “illuminated” us and placed that idea there. Thus, rationality is divine.

            To equate Augustine back to Plato, both philosophers believed that it was impossible to attain knowledge through the perceptible world. This idea stems from Platonic theory of knowledge in that the material world (the first layer of Plato’s Divided Line) is ever changing and unreliable as a source of information. Just as Plato believed it was an impossible source of information about his Good, which we can liken to Augustine’s God, there is no way for Augustine to learn about God through a shifting world when he desires to know about the eternal God. Augustine did not hold the belief that we form abstract concepts from seeing multiples of certain objects, or learning of a concept, but also through illumination, equatable to Plato’s belief that one must “remember” abstract concepts, or Forms.

            Both philosophers place much importance on the faith one must have in God through mystical experience, but treat sensory information very different. Aquinas, contrary to Augustine, was quite the empiricist. As he drew on Aristotle, who was also an empiricist, Aquinas believed the senses are that through which we find the truth. Aquinas, along with Aristotle, believed that abstraction is a process that takes place in the human mind. A person, after seeing multiple material objects, such as a basket ball, will be able to abstract the general form of the object, thus being able to construct the abstract idea of a basketball in their mind, which would be a process done by the “active intellect”.  Aquinas expanded upon Aristotle’s ideas of the intellect and how we understand information. Aquinas argued that the intellect understands “phantasms”, or internal copies of what we perceive, by abstracting. The “passive intellect” is the part of the intellect that knows material objects, that which Aquinas believed is how we know all objects. To understand phantasms, we need the passive intellect to understand what we are seeing. The active intellect is the part of the intellect able to abstract from knowledge of the passive.

            Both Aquinas and Augustine agree upon the fact that God is the object of ultimate knowledge. The philosophers would see eye to eye on the fact that one can know God through reason, while no one can know or understand God fully because man is but God’s creation.

            While both of these theologians and philosophers maintained ideals greatly influenced by Christianity, they both reconciled their beliefs in very different ways. Augustine was very much influenced by Plato, whereas Aquinas was guided very intensely by Aristotle. The ancient philosophers had extreme sway on both Augustine and Aquinas, and it showed in their philosophies of faith and reason, the soul, and knowledge greatly. One concept the two were in agreement on, despite the many differences they had, is that God was the object of human all three of these topics.

Augustine. “Johannis Evangelium Tractatus.” S. Aurelii Augustini … Contra Epistolam Parmeniani Liber II.- S. Aurelii Augustini … Epistola Ad Bonifacium.- S. Aurelii Augustini … In Divi Johannis Evangelium Tractatus XXVI.- S. Aurelii Augustini … Epistola Prior Ad Januarium.- S. Aurelius Augustinus Hilario, Respondens Ad Illius Quæstiones. N.p.: n.p., 1843. N. Min. 18. 19.15 Print.

Augustine, and George G. Leckie. On the Immortality of the Soul (De Immortalitate Animae). New York: D. Appleton-Century, 1938. Print.

McInerny, Ralph and O’Callaghan, John, “Saint Thomas Aquinas”, The Stanford Encyclopedia of Philosophy (Winter 2010 Edition), Edward N. Zalta (ed.), URL = <;.

Swindal, James. “Faith and Reason.” Internet Encyclopedia of Philosophy. IEP, 22 Oct. 2008. Web. 01 May 2013. <;.



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: