Read Along: Christian Apologetics Ch10

Today we continue with chapter ten of Read Along with Apologetics315, a weekly chapter-by-chapter study through Christian Apologetics: A Comprehensive Case for Biblical Christianity by Douglas Groothuis. Please leave a comment on your reading below. This is where you can interact with others reading the book, ask questions, or add your own thoughts. Series index here. Click below for the audio intro, chapter 10 study questions PDF, and summary:

[Audio Intro] - Dr. Groothuis introduces this chapter.
[Chapter 10 Study Questions] (with kindle locations) - PDF study guide.
[Podcast Feed RSS | Podcast in iTunes] - Click to subscribe to the audio.

Summary
Chapter Ten: The Ontological Argument
(pages 185-206)
Chapter ten unpacks the ontological argument for God's existence. The author describes the argument, then examines three formulations of the argument. The first two formulations come from St. Anselm. These argue for the existence of God from the idea of God as the greatest conceivable being, as well as God as a necessary being. The author shows the most common objections to these formulations and defends against the objections.

The third formulation of the ontological argument is by Alvin Plantinga, which argues for the existence of God based on the idea that God is a logically necessary being which, if He is exists in some possible world, must therefore exist in all possible worlds. Again, Groothuis defends the argument against common objections. He also shows that these arguments are much stronger than popular detractors (such as Richard Dawkins) would make them out to be.

Notable quotes:

The ontological argument claims that proper reasoning about the idea of a Perfect Being generates the conclusion that God exists.' For this argument, God's existence is not merely possible or probable or very likely, but is logically guaranteed. (Christian Apologetics, p. 185) 

If the concept of God is not im-possible, then God must exist in at least one possible world, and in that possible world God's existence is necessary. That is, God cannot not exist. So, if God exists as a logically necessary being in one world, he exists as such in all worlds. (Christian Apologetics, p. 200)

Philosophers have proposed other ontological parody arguments for quasi-deities (gods something less than perfect) and for perfect devils. But in each case, the entity lacks the qualities possessed by a Perfect Being. A quasi-deity lacks perfection by definition. (Christian Apologetics, p. 202)  

 Discuss

1. Do you find the ontological argument convincing? Why or why not?
2. Which version of the argument do you find most robust or defensible? Why?
3. Would you ever use the ontological argument in an apologetic interaction? How?

Next week
Chapter Eleven: Cosmological Arguments