The author was a priest in the Catholic Church and subsequently left it as he slowly lost faith in its teachings. He then began a life-long literary career until his death in 1955. He translated over 200 books and some 300 titles under Haldeman-Julius Publications and became know as the "world's greatest scholar." Quoted from the author's "Introduction."
"The word "Rationalism" is used in so many different senses by different writers that it is hardly possible to define it offhand. The intellectual method, or attitude, or spirit which is suggested by it has inspired suchvaried systems in the controversial struggle of the last few centuries that it can no longer be said to describe any actual system with clearness. It is applied equally to Agnosticism, the extreme form of heterodoxy, and to a certain theological school that professes to remain within the precincts of the orthodox temple; and it is
frequently taken to be synonymous with a destructive system of Biblical criticism. Rationalism, in the earlier part of the eighteenth century, meant a school of anti-Christian Deists in England and France; towards the close of the century, and in the earlier part of the
nineteenth century, it was a system of Biblical criticism of a more or less destructive character; modern Rationalism is a system which rejects both natural and supernatural theology, and is antagonistic to the orthodox Churches on every point. The term is, however, still often used in its earlier senses."
"Yet it is easy to trace through all these systems, divergent and even contradictory as they seem to be, the operation of one and the same spirit. The Deist rejected supernatural religion, but emphatically retained belief in a personal God; whereas the modern Rationalist declines all Theistic belief --- or, at the most, retains only a profession of the most evanescent character. But the principle which actuated the departure from orthodoxy was the same in both cases: it was merely discovered to have a deeper application by the later generation. Both schools, and indeed all systems to which the name is applied, accepted as their primary and fundamental principle that reason is the supreme criterion of all truth, whether in secular or religious, natural or supernatural, spheres. Any thesis, on whatever authority it may be asserted, which violates the dictates of reason must be rejected. On that test were rejected, first the mysterious rites and dogmas of Christianity, then its sacred literature, and, finally, even the positions of natural theology. From Collins and Shaftesbury to
Mill and Huxley the history of Rationalism is but a consistent and progressive application of that principle."
"Rationalism, therefore, is rather a "cast of thought" and "bias of reasoning," as Mr. Lecky says, than a stereotyped system. From all time there have been religious statements current among all nations which purported to come from a source other than the natural activity of the human mind, from a higher authority, before which the vast majority of mankind have bent
in feeble and unquestioning submission. Sooner or later a departure from that attitude is inevitable. Reason claims its right as the ultimate test of all truth, applies its first principles and the knowledge it has already acquired to all ethical and religious traditions, and comes to reject a greater or less section, or even the whole, of the inherited creed. The Rationalistic spirit is, therefore, a critical action of reason on authoritative religious tradition, which leads to its partial or entire rejection, either from defect of satisfactory evidence to recommend it, or because it conflicts with known facts or evident moral or speculative principles." pp. 7-8.