No one has more clearly, boldly, and unanswerably enunciated this open and irreconcilable opposition between the modern scientific and the outworn Christian view than David Friedrich Strauss, the greatest theologian of the nineteenth century. His last work, _The Old Faith and the New_, is a magnificent expression of the honest conviction of all educated people of the present day who understand this unavoidable conflict between the discredited, dominant doctrines of Christianity and the illuminating, rational revelation of modern science--all those who have the courage to defend the right of reason against the pretensions of superstition, and who are sensible of the philosophic demand for a unified system of thought. Strauss, as an honorable and courageous free-thinker, has expounded far better than I could the principal points of difference between "the old and the new faith." The absolute irreconcilability of the opponents and the inevitability of their struggle ("for life or death") have been ably presented on the philosophic side by E. Hartmann, in his interesting work on _The Self-Destruction of Christianity_. When the works of Strauss and Feuerbach and _The History of the Conflict between Religion and Science_ of J. W. Draper have been read, it may seem superfluous for us to devote a special chapter to the subject. Yet we think it useful, and even necessary for our purpose, to cast a critical glance at the historical course of this great struggle; especially seeing that the attacks of the "Church militant" on science in general, and on the theory of evolution in particular, have become extremely bitter and menacing of late years. Unfortunately, the mental relaxation which has lately set in, and the rising flood of reaction in the political, social, and ecclesiastical world, are only too well calculated to give point to those dangers. If any one doubts it, he has only to look over the conduct of Christian synods and of the German Reichstag during the last few years. Quite in harmony are the recent efforts of many secular governments to get on as good a footing as possible with the "spiritual regiment," their deadly enemy--that is, to submit to its yoke. The two forces find a common aim in the suppression of free thought and free scientific research, for the purpose of thus more easily securing a complete despotism.