"The present study of the monistic philosophy is intended for thoughtful readers of every condition who are united in an honest search for the truth. An intensification of this effort of man to attain a knowledge of the truth is one of the most salient features of the nineteenth century. That is easily explained, in the first place, by the immense progress of science, especially in its most important branch, the history of humanity; it is due, in the second place, to the open contradiction that has developed during the century between science and the traditional "Revelation"; and, finally, it arises from the inevitable extension and deepening of the rational demand for an elucidation of the innumerable facts that have been recently brought to light, and for a fuller knowledge of their causes"--Preface. (PsycINFO Database Record (c) 2010 APA, all rights reserved).