Post Author: Bill Pratt
In part 4 we introduced being and goodness. In part 5 we analyze ultimate being, or what Christians call God.
As metaphysics is the study of being, the question arises: what is ultimate being? Aquinas reasoned that given any change in the world (a movement from potency to act), there must exist a being who is changeless, who is pure actuality with no potency. Joseph Owens summarizes the argument:
Every sensible thing . . . has its being from something else. . . . Its nature, prior to the reception of being from an efficient cause, has no existence at all. Its nature, accordingly, cannot produce its own being. Its being is caused efficiently by an agent other than itself. If that agent in turn exists through an act of being that is accidental and prior to its own nature, it will similarly depend upon another agent for its proper being. It will be a caused cause, in the order of efficient causality.
The series of causes will have to continue. Even an infinite regression of these caused causes, however, would not account for the least being in the world. In every instance and in all the instances together there would be only nature that contained no being, nature that merely remained open to receive being from something else. There would be an infinite series of existential zeros. . . . This means that for any series of efficiently caused causes there is a first cause. It is first in the sense that it does not have its being from anything else.
Thus Aquinas concludes that “it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.”
From God existing as pure actuality, reason leads us to several other attributes of God. “Since being is the act of all acts and the perfection of all perfections, where it subsists it will be perfection in the highest degree. . . . It therefore contains within itself the perfections of all other things.”
From pure actuality and from the perfections deduced from observation of the world, we reason that God must be immutable, immaterial, eternal, intelligent, volitional, morally perfect, omniscient, omnipotent, simple, omnisapient, and so forth. God is the greatest conceivable being.
With the conclusion of this 5-part series, we have introduced a handful of basic concepts from classical Christian metaphysics. Armed with act and potency, form and matter, the four causes, being and goodness, and, most importantly, God as ultimate being, we can now construct a foundation for Christian ethics. That is the task we take up in another blog post series.