TW facebooked me with this: "I've recently finished reading Sam Harris' book on free will and I was wondering, since [Plantinga's] refutation [of Mackie's logical argument against God's existence] depends on free will, what some of the stronger logical arguments for the existence of free will are?"
I have not come close to reading all that has been written on free will. Nevertheless, I recommend:
- University of Texas philosopher Robert Kane's A Contemporary Introduction to Free Will. Kane is an Incompatibilist. For terminology see here.
- Here is Kane's "Reflections on Free Will, Determinism and Indeterminism"
- Here's a nice, and long, video of Kane speaking about libertarian free will and incompatibilism.
- Here is a nice list of collected essays on determinism and free will.
- For a comprehensive collection see The Oxford Handbook of Free Will, edited by Kane. See especially Part IV - "Libertarian Perspectives on Free Agency and Free Will."