To any reader who has studied Calvin, then turned to the so-called Calvinist tradition, the absence of Calvin's name and, more importantly, of some of his characteristic emphases from the writings of the majority of the theologians who took his name is a striking fact. That some profound transformation of Calvin's ideas, despite the ubiquity of the 'Institutio', took place in the generation after his death is incontrovertible. What has long passed, for example, as the Calvinist doctrine of predestination, whether among its proponents or opponents, is not what one reads in Calvin himself.
This work does much to trace the complex process whereby a scholastic, metaphysical edifice replaced the dynamic, experiential, historically, and exegetically grounded faith enunciated by Calvin himself. Armstrong writes in his Introduction, It is hoped, then, that this study will both provide an introduction to the intellectual trends within French Calvinism, to the teaching of Amyraut and the relation of his thought to that of Calvin, and furnish an insight into the removal of orthodox Calvinist thought from Calvin into a narrower, more defensive, more intolerant, and more impervious system.
Armstrong's study is a full, careful, and engrossing one. It is to be commended not only to readers of theological interest, but to all persons interested in intellectual history, and especially to Christians of the Reformed tradition who are seeking to understand their intellectual and spiritual roots.
from a review by F. L. Battles, Theology Today