Augustine of Hippo lived at the end of the Roman Empire (indeed the final collapse of the western part of the empire happened less than 50 years after his death), and he is sometimes grouped with the philosophers of the Middle Ages. On Free Choice of the Will is an early work and wider ranging than the title might suggest. It’s a short work but Pereboom includes only selections—from the beginning and end of the second of the three “books” into which it is divided and from the beginning of the third. I’ve assigned only the last of these selections, so the assignment is only the latter part of Pereboom’s selection 4.
The chief issue Augustine addresses in this selection is a traditional one regarding freedom of the will—namely, the reconciliation of free will with God’s foreknowledge of the future. Although this is traditionally formulated as a theological issue (and that’s the form in which Augustine addresses it), it might be held that laws of nature (whatever their source) make the future knowable in principle, whether or not we are in fact able to know it. And the question then arises whether this knowability is consistent with freedom of the will. Of course, it doesn’t follow that what Augustine says about God’s foreknowledge applies also to this broader question, but the questions are related closely enough that I’d suggest you think about both.
In the background of the main discussion of this selection, you will notice a distinction between unchangeable, common, and higher good on the one hand and changeable, more particular, and inferior goods on the other. Although these ideas are discussed most fully in parts of book II that aren’t included in the Pereboom anthology, you can find some discussion of them on pp. 23-25, shortly before your assignment begins.