Koons (1998) points out that "In effect, Plato makes a transition to a form of the design argument, inferring the intelligence and goodness of the designer from the perfection of the design."
Aristotle reaches the same conclusion as Plato with respect to God's being an "immaterial being" that "must be a mind" (Koons). He delves further than Plato into why this is so, differentiating between the potential and the actual (Koons). Aristotle views something that endures a "primary" substance, and every "substance has a fixed essence, which determines which properties or attributes it can possess, either potentially or actually" (Koons). Since a substance's potential properties "are constant over time: what changes is which of these properties are actual and which are not" (Koons). Relating this back to his doctrine of God, "Aristotle argues that the First Cause must be a being of 'pure act', a being whose nature it is to be actual" (Koons). This implies that for the First Cause, potentiality and actuality are the same, suggesting that "the First Cause is immutable, since it lacks exactly that feature that explains the changeability of other substances" (Koons). Using these criteria, Aristotle builds a concept of God in which He is simply "a mind that eternally contemplates itself, and only itself" (Koons). Aristotle sees God as changeless, since "Intellectual contemplation is an activity, but it is one that does not entail change" since a being that has perfect self-knowledge "need experience no variation or undulation at all" (Koons). Aristotle also attributes motion in the world to the First Mover by virtue of its "being immediately present to certain subsidiary intelligences (such as the celestial intelligences responsible for heavenly movements) and by inspiring these intelligences to emulate the perfection and happiness of the Unmoved Mover" (Koons).
Lloyd P. Gerson, in his book Aristotle and Other Platoni...
Aristotle's Doctrine of God. (1969, December 31). In LotsofEssays.com. Retrieved 20:15, September 25, 2016, from http://www.collegetermpapers.com/viewpaper/1303485550.html