St. Thomas Aquinas and St. Augustine: Existence, Free Will, and Divine Illumination
St. Thomas Aquinas: Essence and Existence
II) The act of being or existence (esse) is unique for each substance. According to St. Thomas, the contingency of substances means that we can mentally understand their concept or definition without them necessarily existing in reality. Therefore, in contingent substances, essence and existence are really distinct. If essence is pure potentiality or possibility of being, the act of being or existence actualizes the essence. It is the act by which each substance exists or has being (esse).
b) St. Thomas notes both the contingency of the world and the dependence of all creatures on their Creator, God. Only in God are essence and existence the same, because God alone’s essence implies existence; God’s essence is to exist. Therefore, God is the same Self (Ipsum Esse), without any mixture of potential, infinitely perfect, pure act from which all created beings have received their being.
St. Augustine
1 – Free Will and Original Sin
a) St. Augustine questioned the origin and legitimacy of evil, departing from the Manichaeism he followed in his youth, which affirmed the existence of two principles: one good and one evil. St. Augustine followed Plotinus, who understood evil as a “privatio boni,” that is, as a lack or imperfect reality.
b) All that exists is good, as created by God for good (Genesis), and evil is a consequence of an imperfection or lack inherent in matter. In the case of human evil, it is a result of the fallen nature of man, i.e., original sin.
c) St. Augustine believes that God created man free (provided with free will) so that man can choose his actions and thus be responsible for the reward or punishment imposed by divine justice. For Augustine, the willingness to follow the law of God is freedom, while the will turned away from God and toward evil is the “servant-will” and therefore not true freedom, as a consequence of original sin’s weakness and collapse.
d) Contrary to Pelagianism, which held that grace was given once and for all to human nature, which has a good “innateness,” St. Augustine, on the contrary, maintains that because of original sin, human free will has no chance of salvation on its own, because sin has lost grace. Hence the need for further divine intervention for salvation: the freedom of man is that freedom restored, recapitulated in Christ through faith.
2 – Theory of Light (Divine Illumination)
a) St. Augustine is always calling us inward to our inner experience, and the reason for this is because the path that leads to God is within us. One of the ways this manifests is in our attempt to prove the existence of God. The demonstration that St. Augustine makes in the first person is:
- I am conscious of perceiving and thinking, and in thinking about it, I realize that the criteria by which my reason operates, i.e., my ideas, which are required for all who reason, are not truths that each person builds on themselves, but represent common, universal standards.
- So, I recognize that this activity, which is mine, is based on something and implies something that is not our product.
3 – God as Truth
Hence we see that there is something greater than the human mind, that is God, Q.E.D. God = truth exists. The truth is not in me. I see the truth “in” God (Divine Illumination).
• Q.E.D. are the abbreviations of “quod erat demonstrandum,” meaning “which had to be demonstrated.”