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 "Preface."
"The term "Rationalist" first appears in English letters about the middle of the seventeenth century (Clarendon, State Papers, II, App. XL). It denotes a sect who follow "what their reason dictates to them in Church or State." Bacon had a little earlier (Apophthegms, II, § 21) applied the term "Rationals" to the philosophers who sought to attain truth by deductions
from the first principles which reason was supposed to perceive rather than by induction from the observed facts of nature. In neither sense did the term pass into general currency at the time; but in the course of the nineteenth century it has been adopted as the most fitting name for those who uphold what is vaguely called the supremacy of reason in the discovery and establishment of truth."
"The technical use of the term in philosophy is not regarded in the compilation of this DICTIONARY. It still denotes, in the Baconian sense, those who advocate deductive and transcendental rather than inductive or empirical systems of thought. But, since induction is no less a process of reason than deduction, the distinction is not happily framed, and it does little more than designate the tendency to attach value to metaphysical speculation as distinct from the empirical or scientific study of nature. The modern Rationalist may choose either method or, in separate fields of investigation, both. His characteristic is that in the ascertainment of fact he affirms the predominance and validity of reason over revelation, authority, faith, emotion, or instinct; and general usage has now confined the term to those who urge this predominance of reason in regard to the Christian religion. In matters of
State the rights of reason are theoretically admitted."
"Rationalism is therefore primarily a mental attitude, not a creed or a definite body of negative conclusions. No uniformity of opinions must be sought in the thousands of men and women of cultural distinction who are here included in a common category. The one link is that they uphold the right of reason against the authority of Church or tradition; they discard the idea of revelation as a source of truth, and they deny the authority of a Church or a creed or tradition to confine the individual judgment. Yet this common link is overlaid in this series of little biographies with so much variety of opinion, and the title to be called Rationalist in this sense is now so frequently claimed by men who linger in some branch of the Christian Church, that a more precise statement is needed."
"Rationalism has, like every other idea or institution, evolved; and the earlier phases of its evolution still live, in some measure, side by side with more advanced stages of rebellion. Both from the pressure of environment, the nature of the human mind, and the comparative poverty of positive knowledge in the seventeenth and eighteenth centuries, it was natural that Rationalism should first take the form of a simple protest against the supernatural and sacerdotal elements of the prevailing faith. The Socinians or early Unitarians were the first Rationalists, in the period which this DICTIONARY covers. I am not concerned with what we may call the Rationalists of earlier civilizations, and do not propose to include a list of all the thinkers of ancient Greece and Rome, Persia and Arabia.* For the same reason I omit entirely the long list of Chinese and Japanese scholars, all of whom are Rationalists, and nearly all of whom are Agnostics. Nor do I propose to include the names of early Rationalizing Christians like Abelard and Arnold of Brescia, the Epicureans and Materialists and Cathari of the thirteenth and fourteenth centuries, or even the Humanists and Neo-Pagans of the Renaissance. In order to stress the full significance of the modern development, these earlier outbreaks or phases of rebellion are omitted. The period which this DICTIONARY covers begins at the death of Giordano Bruno in the year 1600."
This dictionary contains some 2200+ biographical sketches of modern free thinkers. An excellent companion to this volume is McCabe's "Judged! What 500 of the World's Outstanding Figures […] Have Said About the Roman Catholic Church" and Noyes' "View of Religion" which has about 6000 quotes on what great thinkers have thought about Christianity.
* McCabe covers these early rationalists in his "Biographical Dict6ionary of Ancient, Medieval, and Modern Freethinkers." This work covers about 750 thinkers of the ancient, medieval and modern world.