The profile of the natural law presented by St. Thomas Aquinas is not final; none is. But we have seen how painfully and painstakingly it was constructed, based upon the elements in a complex and age-long tradition and combining those elements in a new synthesis. It was not to be expected that this synthesis could remain unchanged — it must be adapted to new ages and new problems. It is the argument of this book that it is eminently capable of adaptation to the problems of our age, that it is still the best guide we have to morality. It must be seen, however, for what it is, with all its original flexibility and adaptability, and be purged of excrescences and misconceptions, the products of later ages. In this chapter and the following one we may take a selective look at the post-Thomistic history of the natural law in order to see how Thomas's concept was deformed and to discern how it may be recovered for our present instruction. There are two major turning-points in that history. The first, found in the nominalistic controversies from the fourteenth century down to and beyond the Reformation, will be the subject of this chapter; the second, the rise of the" secular natural law" in the seventeenth and eighteenth centuries, will occupy the next chapter.