It is easy to see that a work thus corrected after so long an interval, could never acquire the unity and rounded completeness which only belong to such as are written in one breath. So great a difference will be found even in style and expression, that no reader of any tact can ever be in doubt whether it be the older or younger man who is speaking. For the contrast is indeed striking between the mild, unassuming tone in which the youth--who is still simple enough to believe quite seriously that for all whose pursuit is philosophy, truth, and truth alone, can have importance, and therefore that whoever promotes truth is sure of a welcome from them--propounds his arguments with confidence, and the firm, but also at times somewhat harsh voice of the old man, who in course of time has necessarily discovered the true character and real aims of the noble company of mercenary time-servers into which he has fallen. Nay, the just reader will hardly find fault with him should he occasionally give free vent to his indignation; since we see what comes of it when people who profess to have truth for their sole aim, are always occupied in studying the purposes of their powerful superiors, and when the _e quovis ligno fit Mercurius_ is extended even to the greatest philosophers, and a clumsy _charlatan_, like Hegel, is calmly classed among them? Verily German Philosophy stands before us loaded with contempt, the laughing-stock of other nations, expelled from all honest science--like the prostitute who sells herself for sordid hire to-day to one, to-morrow to another; and the brains of the present generation of _savants_ are disorganised by Hegelian nonsense: incapable of reflection, coarse and bewildered, they fall a prey to the low Materialism which has crept out of the basilisk's egg. Good speed to them. I return to my subject. My readers will thus have to get over the difference of tone in this treatise; for I could not do here what I had done in my chief work, that is, give the later additions I had made in a separate appendix. Besides, it is of no consequence that people should know what I wrote in my twenty-sixth and what in my sixtieth year; the only matter of real importance is, that those who wish to find their way through the fundamental principles of all philosophizing, to gain a firm footing and a clear insight, should in these few sheets receive a little volume by which they may learn something substantial, solid, and true: and this, I hope, will be the case. From the expansion now given to some portions, it has even grown into a compendious theory of the entire faculty of knowing, and this theory, by limiting itself strictly to the research of the Principle of Sufficient Reason, shows the matter from a new and peculiar side; but then it finds its completion in the First Book of "The World as Will and Representation," together with those chapters of the Second Volume which refer to it, and also in my Critique of Kantian Philosophy.