One of the main streams of Ideas contending for dominance in our culture Is the Judeo-Christian tradition. This tradition had Its origin In religion, but interacted with philosophy to such a degree that it produced a unique world outlook with its own unique sense of life. In these lectures, the fundamentals of the Jewish and Christian religions are outlined historically and analytically so as to reveal their common features and their differences. The over-all world outlook is analyzed as a quasi-philosophical system, having a characteristic metaphysics, epistemology, ethics, and politics. The corresponding sense of life is studied in terms of personal and sexual relations, child-rearing, and attitudes affecting economics. The special problems of a rational philosophy in confronting the Judeo-Christian tradition are considered. The lectures conclude with an estimate of the prospects for the victory of reason in this struggle.