THE thought which may first occur to us in the history of Philosophy, is that the subject itself contains an inner contradiction. For Philosophy aims at understanding what is unchangeable, eternal, in and for itself: its end is Truth. But history tells us of that which has at one time existed, at another time has vanished, having been expelled by something else. Truth is eternal; it does not fall within the sphere of the transient, and has no history. But if it has a history, and as this history is only the representation of a succession of past forms of knowledge, the truth is not to be found in it, for the truth cannot be what has passed away. It might be said that all this argument would affect not only the other sciences, but in like degree the Christian religion, and it might be found inconsistent that a history of this religion and of the other sciences should exist; but it would be superfluous further to examine this argument, for it is immediately contradicted by the very fact that there are such histories. But in order to get a better understanding of this apparent contradiction, we must distinguish between the outward history of a religion or a science and the history of the subject itself. And then we must take into account that the history of Philosophy because of the special nature of its subject-matter, is different from other histories. It is at once evident that the contradiction in question could not refer to the outward history, but merely to the inward, or that of the content itself. There is a history of the spread of Christianity and of the lives of those who have avowed it, and its existence has formed itself into that of a Church. This in itself constitutes an external existence such that being brought into contact with temporal affairs of the most diverse kind, its lot is a varied one and it essentially possesses a history. And of the Christian doctrine it is true that it, too, has its history, but it necessarily soon reached its full development and attained to its appointed powers. And this old creed has been an acknowledged influence to every age, and will still be acknowledged unchanged as the Truth, even though this acknowledgment were become no more than a pretence, and the words an empty form. But the history of this doctrine in its wider sense includes two elements: first the various additions to and deviations from the truth formerly established, and secondly the combating of these errors, the purification of the principles that remain from such additions, and a consequent return to their first simplicity.