In Chapter 3 of Handbook of Christian Apologetics (hereafter: HOCA), Peter Kreeft and Ronald Tacelli present twenty arguments for the existence of God. The very first argument is one of the Five Ways of Aquinas. This is not surprising, since Kreeft is a Catholic:

The universe is the sum total of all these moving things, however many there are. The whole universe is in the process of change. But we have already seen that change in any being requires an outside force to actualize it. Therefore, there is some force outside (in addition to) the universe, some real being transcendent to the universe. This is one of the things meant by “God”.

Briefly, if there is nothing outside the material universe, then there is nothing that can cause the universe to change. But it does change. Therefore there must be something in addition to the material universe. But the universe is the sum total of all matter, space and time. These three things depend on each other. Therefore this being outside the universe is outside matter, space and time. It is not a changing thing; it is the unchanging Source of change. (HOCA, p.50-51)

There may be more than one argument in this passage, but one line of reasoning here goes something like this:

1. If there is nothing outside the material universe that can cause the material universe to change, then there is nothing outside the material universe that is causing the material universe to change.

2. If there is nothing outside the material universe that is causing the material universe to change, then the material universe is not changing.

Thus:

3. If there is nothing outside the material universe that can cause the material universe to change, then the material universe is not changing.

4. But the material universe IS changing.

Thus:

5. There is something outside the material universe that can cause the material universe to change.

6. The statement “There is something outside the material universe that can cause the material universe to change” means the same thing as “God exists”.

Therefore:

7. God exists.

The intermediate conclusion is premise (5), but (5) does not say anything about God, so another premise is required in order to get the desired conclusion (7) that God exists. Premise (6) provides a logical bridge between (5) and (7) by asserting that two different statements have the same meaning.

But premise (6) is clearly false. The two statements in question are NOT equivalent in meaning. For example, the claim that ‘There is something outside the material universe that can cause the material universe to change” does NOT entail that ‘There is a person who is perfectly morally good’. But ‘God exists’ does entail that ‘There is a person who is perfectly morally good’. (7) entails something that (5) does not entail, so (7) does not have the same meaning as (5).

Premise (6) appears to involve a confusion between sense and reference. It might be the case that the expression ‘something outside of the material universe that can cause the material universe to change’ refers to the same being as the expression ‘God’, but these two expressions don’t have the same meaning or sense. We can improve upon the above argument for the existence of God, by reformulating (6) to be a claim about the reference of the two expressions, rather than about the sense or meaning of the expressions:

(6A) The expression “something outside the material universe that can cause the material universe to change” and the word “God” both refer to the same being.

Kreeft would need to come up with an argument to support premise (6A), but at least it is not obviously false like the original premise (6), and it does the job of providing a logical link between premise (5) and the conclusion (7).

However, premise (6A) in combination with some other assertions made by Kreeft, plus a claim about the logical incompatibility of timelessness and perfect freedom (defended by Richard Swinburne), allows us to build an argument against the existence of God:

(6A) The expression “something outside the material universe that can cause the material universe to change” and the word “God” both refer to the same being.

Therefore:

(8) If God exists, then there is something that has all of the divine attributes and that is outside of the material universe.

(9) If something is outside the material universe, then it is outside of space and time.

Thus:

(10) If God exists, then there is something that has all of the divine attributes and that is outside of space and time.

(11) One of the divine attributes is being a perfectly free person.

Thus:

(12) If God exists, then there is something that is a perfectly free person that is outside of space and time.

(13) It is NOT the case that there is something that is a perfectly free person that is outside of space and time.

Therefore:

(14) It is NOT the case that God exists.

Based on what Kreeft says in spelling out the first argument for the existence of God in Chapter 3 of HOCA, I believe that Kreeft would accept every premise of this argument with the exception of premise (13). But premise (13) is well defended by Richard Swinburne.

According to Swinburne if God is outside of time, then God is totally immutable. But if God is totally immutable, then God is NOT a perfectly free person (The Coherence of Theism, revised ed., p.222) So, if something is outside of time, then it cannot be a perfectly free person. But one of God’s divine attributes is being a perfectly free person, so it is incoherent to assert that ‘God is totally immutable’, or to assert that ‘God is outside of time’.

Swinburne has another argument for the incoherence of the assertion that ‘God is outside of time’, which is based on the trasitivity of simultaneity: If A is simultaneous with B, and B is simultaneous with C, then A is also simultaneous with C. (See The Coherence of Theism, Revised edition, p.228). I won’t spell out this other argument for the incohernce of the assertion ‘God is outside of time’, but Swinburne does make a strong case that this assertion makes a self-contradictory statement, and thus is necessarily false.