My subject therefore begins everywhere, even though it is a specialty. Hence I take the liberty to take my departure from any literature which I happen to study. In the present letter, I deal with "logical investigations" of the prominent Professor Trendelenburg. His is a bulky volume, but you need not fear that I shall weary you with its subtleties. As a rule I read only the preface of philosophical works of the second and third order, their introduction and perhaps the first few chapters. Then I am approximately informed as to what I may expect from them further on. One frequently finds statements which, if they do not throw new light on the subject, still bring out in bolder relief some of the accomplishments of historical research in our field. And in order that the son may not trust to the father alone, which might lead to distrust, I connect my argument with some statements of Trendelenburg. In the preface to the second edition the author complains of the "dull headache" which the Hegelian intoxication has left in Germany and says: "Philosophy will not resume its old power until it becomes consistent, and it will not become consistent until it grows in the same way that all other sciences do. In other words, it must not take a new departure in every brain and then quit, but it must approach its problems historically and develop them. The German prejudice must be abandoned, according to which the philosophy of the future is supposed to look for a new principle. This principle has already been found. It consists in the organic world conception, the fundaments of which are resting in Plato and Aristotle." The Professor is right, but he overlooks that the philosophers, even of modern times, do not begin "each on his own account," do not have "each his own principle," or if they have, such a "false originality" is but the indifferent attribute of historical development which has handed the object of logic, the true art of thought, from generation to generation in an ever brighter condition. I repeat this emphatically for pedagogic reasons, because I consider it essential to convince you and the reader that the apparent paradoxes which I state are the objects of discussion since time immemorial. I also wish to stimulate you to a study of the master works of philosophy which show the cheering spectacle, in the persons of the most brilliant specimens of the human mind, of the onward march of this mind from darkness to light. In order that the wheat contained in this human treasure box may not be concealed by the tares, I am endeavoring to throw light on the outcome of the historical development of philosophy, and for this purpose I continue to discuss the question by taking my departure in this instance from some further statements of Trendelenburg.