Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/392

364PROP. XVIII.———— preceding ones, several good reasons may be alleged for introducing them. The student of philosophy is never more perplexed than when he is brought into contact, again and again, with the same error expressed in different language, and with the same controversy carried on under an altered nomenclature. In such cases he is perplexed, because the new phraseology leads him to suppose that something different from what had formerly been before him is being treated of. When he knows that this is not something different, but the same, he is perplexed no longer. To obviate, therefore, this cause of embarrassment, it is proper to follow out the same error through all the disguises which it may assume, in order to show that, under all its aliases, it is merely an old acquaintance with a new face, or rather the same convict trying to impose upon us in a different dress. Error seems to be as tenacious of existence as truth. No sooner is it demolished under one form than it comes to life again under another. It steals, serpent-like, through the world, and, even when convicted, it usually escapes with the loss of little more than the mere skin upon its back. That is hung up in terrorem, but the wearer wanders on in another suit, wily, protean, and inexterminable. It is, therefore, the part of all well-wishers to the truth to keep a vigilant look-out upon the movements of this incorrigible vagrant,—to give notice of his approach, and to unmask him