The word "pietism" usually conjures up a host of ambivalent im pressions. It has seemed to me increasingly clear that many of the strengths of pietism have been swept aside by reactions against the excesses of the movement. To properly assess the structures of pietism, it is important to comprehend its matrix and to understand its ex ponents. In preparing this study, therefore, I have sought to recapture something of the person of Theodorus Jacobus Frelinghuysen as well as the gist of his thought; something of his environment as well as the institutions of his day. To achieve this I have...