I will have a few (maybe several) posts on St. Augustine’s On Free Choice of the Will. I don’t have an online link to this book. Surprisingly to me, it’s not available at New Advent. I presume this is because it is peculiarly omitted from The Nicene and Post-Nicene Fathers series. I am not familiar with the theological predispositions of the editors and translators of NPNF, but it strikes me as odd that this particular work would not be included.
On the other hand, if those editors were of any sort of Reformed stripe that really took seriously (as Calvinists do) their doctrine of predestination, I think we might be able to arrive at an answer. Because if there is anything that On Free Choice of the Will is not, it is predestinarian. It has, admittedly, been a while, but I am at a loss to think of any books by Reformed authors on the subject of man’s free will. My wife suspects that (possibly) Packer’s Evangelism and the Sovereignty of God might have, but even if that’s so, it’s but one book (and by a man that at least some Reformed types aren’t too keen to claim as one of their own). Let us compromise and suggest that there may be some very few books on the subject from the Reformed camp. In general, though, they simply do not write books about it; and in many cases what they write about free will is intended to deny that we have it.
But St. Augustine was not Calvinist. He was not Reformed. He was Catholic. And so he was perfectly willing to write such a book as this, because of course the Catholic Church teaches both that we have a free will and that God has an eternal plan of predestination.
Another striking feature of the book as a whole is that The Doctor appealed to Scripture very little. Most of the argument is strictly philosophical—something else that is doubtless unappetizing to many Reformed. There is also at least one theological oddity that might perhaps embarrass those who disagree with St. Augustine about it…But we’ll save that for a post of its own.
It’s also worth noting, for the sake of those who might try to suggest that On Free Choice of the Will was somehow superseded by St. Augustine’s later writings, that this is quite simply not the case. While in fact it was written very early in his Christian life, he revisited it in his Retractations (near the end of his life) because the Pelagians were ripping quotations from it for their own use. Far from overturning anything that he actually wrote in the book, though, all he does is make clear that they were taking things out of context. In short: he certainly did not repudiate the views in this book. [Source for the material in this paragraph may be found in the Appendix (pp. 151-158) of the edition of On Free Choice of the Will linked above; it includes both the text of the Retractations pertinent to this book and historical notes from the translators].