Proving God Exists – St Thomas Aquinas Denies St Anselm’s Ontological Argument

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God Image from The Creation of Adam by Michaelangelo. Public Domain, Wikimedia Commons

“The Creation of Adam,” painted by Michaelangelo, depicts God among the angels of heaven. Image by Urek Meniashvili.

St Thomas Aquinas (1225-1274) and St Anselm of Canterbury (1033-1109) set themselves the task of proving that God exists.  Both came up with some ingenious theories.

St Anselm started what later became described as the “ontological argument,” which St Thomas Aquinas then took up and developed.

According to Iris Murdoch in Metaphysics as a Guide to Morals, Aquinas did not accept St Anselm’s Proof. However, St Anselm’s concept of God does seem to resonate with Aquinas’ Fourth Proof, the idea that perfection in the imagination must exist in reality.

Saint Anselm – “Faith Seeking for Understanding”

St Anselm, a Burgundian, became Archbishop of Canterbury in 1093.  He battled through several theories, then set to defining his conclusions in his Proslogian.  Anselm claims that God must exist, because the concept of God exists.  The idea of God is synonymous with that of a supreme being, Anselm believes. Nothing greater than the Supreme Being can exist in the imagination, so it must follow that it must exist in reality.

In Metaphysics as a Guide to Morals, Iris Murdoch describes Anselm’s acceptance of the “…invisible in the visible, the uncreated in the created, the great Good in the lesser good.”  Murdoch also speaks of the need for certainty, which she describes as a “dangerous concept.”  She says, “Certainty: clarity. In Anselm’s spiritual life these ideas are intimately connected.”

Dante and Beatrice gaze upon the highest heaven. Gustave Doré. Public Domain, Wikimedia Commons

Dante and Beatrice gaze upon the highest heaven in Paradiso Canto. Painting by Gustave Doré.


Arguments Against Anselm’s Proof

In his own time, St Anselm had his critics.  In “St. Anselm of Canterbury,” Philosophy – 100 Great Thinkers, Jeremy Harwood quotes Gaunilo of Marmoutiers, who says that Anselm’s reasoning allows for many supposedly perfect things that could not possibly exist.

“Anselm’s reply was that it was a mistake to apply his reasoning to argue for the existence of anything other than God,” says Harwood.

Murdoch applies a modern, more psychological approach: “Anselm’s Proof has interested thinkers because it seem so concise and “logical”. But neither its Christian nor its logical charm must be allowed to conceal its fundamental sense. The idea of God, (goodness, virtue) crystallises out of our moral activity.”

St Thomas Aquinas’s Five Proofs

In order to “Christianise” Greek thinking and render it harmless to Christian dogma, St Thomas Aquinas came up with the following Five Proofs, which he published in his Summa Theologica, (Summary of Theology).  Bertrand Russell summarized these in History of Western Philosophy.

  1. From Aristotle, St Thomas Aquinas takes the idea of the unmoved mover. “There are things which are only moved, and other things which both move and are moved. Whatever is moved is moved by something, and, since an endless regress is impossible, we must arrive somewhere at something which moved other things without being moved.”
  2. Now we come to the argument of the First Cause, “…which again depends upon the impossibility of an infinite regress,” explains Russell.
  3. St Thomas Aquinas’s third argument is similar to the first:  “There must be an ultimate source of all necessity.”
  4. This is the argument involving “perfection.”  There are various perfections in the world, which must have a completely perfect source.
  5. St Thomas Aquinas claims that all things, even lifeless things, serve a purpose. That divine purpose must come from some being outside of these things, whether animate or inanimate.  

In short, St Thomas Aquinas believes that all rational knowledge can only be gained through sensory experience. Studying the world shows us the essential nature of things. We must strive for our highest good, believe in Christ as our salvation and as our protection in Heaven and on Earth.

Thomism: A Philosophical Theory to Prove the Existence of God

St Thomas Aquinas’s theory became known as Thomism. Thomism’s attempts to reconcile Aristotelian thinking with Christianity depends on upholding the distinctions between blind faith and reason, therefore, between science and philosophy.

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© Copyright 2013 Janet Cameron, All rights Reserved. Written For: Decoded Past

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