Those thinkers who have completely overlooked the distinction between pleasure with the character of rightness and pleasure which is not so qualified, are in danger of falling into opposite errors. The one class view the matter as though _all_ pleasure had the character of rightness, the other class as though _no_ pleasure were so qualified. By the one class the notion of the good as that which rightly pleases, is entirely given up; “worthy of desire” (begehrenswert) in distinction from “desirable” (begehrbar), is an unmeaning expression. For the other class, “worthy of desire” (begehrenswert) remains as a separate notion, so that there is no tautology in their saying nothing is in itself desirable except in so far as it is in itself worthy of desire, is good in itself. Manifestly they must, to be consistent, assert this, and this they have really taught. The extreme hedonists all belong to this class; but, along with them, many others; in the Middle Ages, for example, the teaching is found in Thomas Aquinas, whose greatness receives fresh appreciation from Ihering (cf. Summ. theol. I.a. qu. 80, qu. 82, art. 2 ad. 1, etc.). But even then such a view cannot be maintained in the light of the facts without exposing the nature of good and bad to a falsification which involves a form of subjectivism similar to that formerly committed by Protagoras respecting the notions of truth and falsehood. Just as, according to this subjectivist in the sphere of the judgment, man is the measure of all things, and often what is true for one, may at the same time be false for another--so the advocates of the view that only the good can be loved, only the bad hated, are really compelled to assume that, in this sphere, each is himself the measure of all things; for the good, in that it is good; for the bad, that it is bad; so that often something is, in itself and at the same time, both good and bad: good in itself, in the case of all who love it for its own sake; bad in itself, in the case of all who hate it for its own sake. This is absurd, and the subjectivistic falsification of the notion of the good is to be rejected equally with the subjectivistic falsification of the notions of truth and existence by Protagoras, but with this difference: that the subjectivistic error in the sphere of what is rightly pleasing and displeasing takes root more easily and infects most ethical systems even to-day. Some, as recently, Sigwart (_Vorfragen der Ethik_, p. 6), confess it openly; others fall into this error without themselves becoming clearly conscious of the subjectivistic character of their view.[A]