Nashotah House

TH 1 / Michaelmas 2000 / September 11

"Proofs for the Existence of God"

Proving God

• Nature of Proof The various arguments that are offered to prove that God exists should be seen as arguments that offer reasons for believing in God, not as offering scientific proof (see Kreeft,24)
• What Aquinas Thought he Was Doing-In view of the possible objections to the five arguments given by St. Thomas, it is unlikely that he thought he was giving "proofs" that would establish the existence of a Creator God with revelation left to supply the remaining knowledge of God (such as the doctrine of the Trinity). St. Thomas starts from a position of faith (acceptance of belief in God), then steps back at this stage to offer arguments based on logical reasons why it is rational to hold such a faith.

Arguments and Objections

2.1 The Ontological Argument (First posed by St. Anselm, used by Descartes and others, including Hartshone in the 20^th century). Somewhat difficult [not used by Kreeft]. Anselm posits the definition of God: That than which nothing greater can be conceived. If God did not really exist, then there would be a contradiction, because the reality of God would indeed be superior to this idea. Thus: if this definition of God is accepted, and it exists in the mind, then the reality must also exist.

Gaunilo's objection: We can imagine an island, defined that one more perfect could not be imagined. Because the reality is better than idea, then it should exist.

Anselm's argument counters: It is only in the case of God where perfection is part of the definition and essence of God. Islands (and other things) are not necessarily perfect, while God is.

In the 18^th century, the philosopher Kant objected (see reading 1.18). When we say that "God exists" we are not adding a new predicate to God (such as "wise" or "loving")

2.2 The "Five Ways" of Thomas Aquinas

• Change: Everything that changes is affected by something else; there must be something changeless
• Efficient Cause: All the secondary causes that exist in the universe require an initial efficient cause.
• Necessity and Possibility: The fact that all things are dependent on other thngs point to the need for a being that exists by itself, not dependent on anything else.
• Standard of perfection There must be an ultimate standard for truth, and perfection for our judgments to have truth value.
• Design The presence of design and purpose in the universe and in creatures and in parts and relations points to a creative mind as origin. [see Kreeft, 24 ff.]

2.3 Objections

Kreeft presents (pp. 33-34) several possible objections and then possible replies, such as the ambiguity of the notion of cause, and the possibility of infinite regress. In addition, however, we might add:

• •Why would there have to be only one unmoved mover?
• •The arguments might point to the existence of God at one time (to get things going), but he could have since ceased to exist (see Wm. Of Ockham).