The Augustinian position with respect to epistemology was based on the idea that intellectual knowledge can essentially be derived from an immediate “enlightenment.”  Man participates in divine thought, and his intellect therefore possesses within itself the ability to create insight.  External things are not the direct cause of our knowledge; they only provide the impulses which cause the subject to form knowledge.  This is called the illumination theory, and it also has significance for the understanding of faith.  True faith is an immediate certainty, inwardly given, an infused or inspired faith (fides inspirata).  This is superior to all authority, and it implies an immediate certainty  about divine things.

The Aristotelian epistemology , on the other hand, is based on the idea that the human subject receives knowledge from without.  In its relationship to the world without, the intellect is passive, and it possesses the ability to recieve the form of things as species intelligibiles, which are transformed from things  to the intellect via sensual impressions.   “There is nothing in the intellect which was not earlier in the senses.”  THis position involves a stronger empiracal interest and a pronounced sense of tangible reality.  This is important also in theology.  The Christian concept of creation is, in a sense, of decisive significance in this tradition.  God is thought to stand in a direct relationship to external reality and to be active also in the temporal order.  The high appreciation of the natural order as an expression of God’s creation which has been characteristic of later Western theology, both within Lutheranism and Roman Catholicism, was promoted by the influence of Aristotelian philosophy.  Its epistemology held, therefore, that knowledge is formed by external impressions.  The soul is a blank slate (tabula rosa), which is able to receive these impressions and thus form logical knowledge.   In the act of knowing , the soul is united with the form of the object which it perceives.   Knowing involved the union of the intellect and the object of knowledge.  The forms which provide the nature of things, and the forms which the intellect receives and absorbs into itself are identical.  According to Thomas Aquinas the soul is,  “in a way, all things”  (quodammodo omnia).  Faith is the be understood in an analogous manner.  Faith is not so much inner enlightenment as it is a form of knowledge similar to others, although it has a different object.  The truth of faith is not empirical but revealed.  This revealed truth comes to man through the authorities (e.g. Scripture), but is has its origins in God’s own truth.  What we have here is a question of supernatural knowledge in contrast to natural knowledge.

The Augustinian and Aristotelian schools also differed with respect to anthropology: in the one case the soul of man was thought of as an independent entity, while in the other soul and body were spoken of as a unit.  But dualism is involved to some extent even in those forms of scholasticism which are otherwise Aristotelian in structure.  Furthermore,  the Franciscan school was voluntaristic, whereas Aristotelianism tended to be intellectual: within the former the will was seen to be the primary factor, ruling in a sovereign manner over one’s actions;  according to the latter point of view the intellect was though to be of prime importance.  The intellect, it was said, influences the will, so that the will desires that which the intellect considers to be good.  This difference of opinion was of significance in the dispute between Thomism and Scotism, just as it was later on in the controversy between the Thomists and the nominalists.