Metaphysical groundwork of the Five ways of St. Thomas Aquinas
By Darko Piknjac
Thesis (Ph.D.)–University of Toronto, 1999
Abstract: The Five Ways are not an instance of what is nowadays understood as the ‘ cosmological argument’. The reason is that the First Cause, or God, to which St. Thomas’ arguments conclude is “the proper cause of the act of being.” (‘Summa Contra Gentiles’, II, 21, 4) But the ‘cosmological’ inquiry, in any of its aspects, does not deal with the act of being. The First Cause encountered in cosmology is insufficient for understanding the God of St. Thomas.
Consequently, St. Thomas’ arguments for God’s existence must be viewed in the context of the intellectual activity that deals with the act of being. This is metaphysics. More specifically, it is the metaphysics centered around existence as the highest act, and as the act exercised by the effects of the First or Proper Cause of the act of being.
Therefore, the context of the Five Ways is that of a philosophical activity in which one tries to reach the ultimate cause in an actual thing of that which ultimately gives it actuality. For St. Thomas, the act of existenceis the actuality of all acts, and is therefore that which gives real things their actuality. But if God is the proper cause of that which makes things in the world actual, then their dependence on the First Cause must first be seen along the lines of their act of being or existence.
It will not do, as many contemporary cosmological interpretations of the Five Ways attempt, to read St. Thomas as arguing only for the ultimate cause of motion or efficient causality in the actual things in the world. The Five Ways are an instance of an existentially metaphysical argument.