The contents of this volume originally constituted about one half of a work, entitled “Faith in God and Modern Atheism compared, in their Essential Nature, Theoretic Grounds, and Practical Influence.” Simultaneously with the first issue of that work in Scotland, the five principal chapters in this volume were published separately, accompanied with the announcement that each was complete in itself. The hint thus given by the author, has been acted upon by the present publishers. On examining the whole work, it was found to be divided into four Sections. Of these, the third was devoted exclusively to “Modern Atheism.” It embraced the five chapters already alluded to, together with a general introduction and four shorter chapters. It appeared, in fact, to be a complete treatise by itself; and it is now presented to the American public in the conviction that such a work is peculiarly demanded by the present state of religious opinion in this country.