Principles of Philosophy is an attempt, by a self-taught genius, to persuade the Yiddish speaking public that philosophy has not lost its central importance vis a vis both religion and science. He does this, first, by identifying religion with philosophy--and he is the first Orthodox rabbi since Maimonides to do so. Next, he argues that philosophical principles, which are broader than those of science, are at the basis of all existence, and that the same principles that account for the organization of matter can account for the varieties of human organization (and disorganization). He argues, finally, that the study of philosophy itself can lead to the weakening of egotism and the strengthening of altruism.