Theo of the Body is one of my next projects. I do have Kreeft’s book but his other work, Handbook of Christian apologetics lists 20 arguments of the existence of God; the first 5 are Aquinas’s but no. 6 is most interesting:
1. whatever begins to exist has a cause for its coming in to being.
2. the universal began to exist
3. Therefore, the universe has a cause for its coming in to being
Most people accept the first premise. Number two has found support from natural science (Big Bang, which has first formulated by a Belgian priest)but which also has philosophical arguments in its favor:
Can an infinite task ever be completed? If, in order to reach a certain end, infinitely many steps had to precede it, could the end ever be reached? No, even in an infinite time. If we had to count to infinity before turning on our computer we would never touch the “On” button.If the universe is infinitely old, then an infinite number of days would have elapsed before say, today. But that’s impossible. So either the present day has not been reached or the process of reaching it was not infinite.
Other favorite reads include “50 questions on the natural law” by Charles Rice and “Catholocism and Fundamentalism” by Keating (highly recommended)