Why must we assume that material existence must be caused by a “eternal, good and self-sufficient” existence that wasn’t caused.
That’s not a case of special pleading, it’s the rational outcome of airtight logical syllogisms, as defended by Plato, Aristotle, Plotinus, Augustine, Boethius, Avicenna, Averroes, Maimonides, Aquinas, Bonaventure, Leibniz, and friends. If you don’t like Professor Kreeft (whom I greatly respect, but does falls under the category of ‘pop philosophy’) then try taking up some of the serious literature. You totally misunderstand the argument. “God” is not a placeholder, or a premise, he is a conclusion.
I’m going to recommend a few books for, essentially, everyone in this thread. They’re relatively basic introductions to the classical theist tradition, but totally invaluable nevertheless.
“
Five Proofs of the Existence of God” by Dr. Edward Feser
Offers five logical proofs based on arguments made by Aristotle, Plotinus, Augustine, Aquinas, and Leibniz. This is probably the best book of natural theology written in the last 15 years.
“
Aquinas: A Beginner’s Guide” by Dr. Edward Feser
This book gives an overview of the thought of Thomas Aquinas, going deeply into his famous “Five Ways” (not to be confused with the Five Proofs discussed previously). A good companion text might be Feser’s “
Scholastic Metaphysics: A Contemporary Introduction”
“
The Experience of God: Being, Consciousness, Bliss” by Dr. David Bentley Hart
As Hart is an Eastern Orthodox philosopher and theologian, this work differs considerably from that of the Neoscholastic Ed Feser. However, I think it is invaluable for anyone who wants to learn what serious believers mean by “God” in the most general sense. He draws upon various Hindu, Jewish, Christian, and Muslim traditions to produce this masterpiece. It’s very dense (in keeping with Hart’s style) yet eloquent, so get out a fine liqueur and go page by page.