The existence of the conscience as a specific and natural faculty of discernment of right and duty may seem to the student or reader to need no formal proof, as something substantially everywhere acknowledged. But as various theories undertake to question its existence, in the sense thus explained, and resolve the affirmations of right and duty into pseudo-products developed in a roundabout way, or by some illusive transformation of ideas or sentiments given by the other faculties of the soul, ideas or sentiments which in fact are really unethical, it becomes necessary to vindicate the asserted existence of this moral faculty. ==Moral Distinctions Prove Conscience.== =1.= The primary and fundamental evidence is the great fact, already set forth, of the moral distinctions which arise out of its action and fill personal consciousness and the life of the world with their attesting presence. The known object implies a power by which it is known. Without the faculty, in the sense of a power to know, the knowledge here in question could not exist. Its existence is proof of the reality and action of the faculty perceptive of it. The only alternative to this would be a total denial of the ethical distinction, even as a genuine phenomenon, and an assertion that the supposed knowledge of it is, and always has been, illusory and unreal. And this would be equivalent to a claim that men may and should abandon the ethical distinction and believe that there is absolutely no moral difference between justice and injustice, between kindness and hatred, between truth and lying, between friendship and treachery, between charity and murder. And this again would mean that we are to repudiate, as without validity, the whole notion which the ages, especially the most intelligent and best ages, have cherished, that man is capable of character, as good or bad, excellent or blameworthy. But this whole alternative becomes impossible, by reason of the necessary and invincible contrary judgment by which the moral distinctions are affirmed as actual and valid for human life. The faculty of moral discernment proves its existence by making the contrary of its discernment an impossible conception. ==The Moral Perceptions Peculiar.== =2.= Its existence is further proved by the unique and peculiar character of its data or perceptions. These are unlike any other, _sui generis_. They are original and cannot be deduced from other data. The ethical percept is something that can be understood only in terms of itself. It cannot be described or expressed in the terms of the percepts or knowledge given by the other faculties of the soul, either general or special, either separately or in combination. Hence we must, according to all sound psychological procedure, postulate a special faculty, as distinctive and normal as is the percept, for this original and irresolvable ethical idea.