Of late years, and by the best writers, the term conscience, and the phrases “moral faculty,” “moral judgment,” “faculty of moral perception,” “moral sense,” “susceptibility of moral emotion,” have all been applied to that faculty by which we have ideas of right and wrong in reference to actions, and correspondent feelings of approbation and disapprobation.

Maimonides is of opinion that the arguments based on the properties of things in Nature are inadmissible, because the laws by which the Universe is regulated need not have been in force before the Universe was in existence.

For, in fact, I say the degree of vision that dwells in a man is a correct measure of the man. If called to define Shakspeare's faculty, I should say superiority of Intellect, and think I had included all under that. What indeed are faculties? We talk of faculties as if they were distinct, things separable; as if a man had intellect, imagination, fancy, &c., as he has hands, feet and arms. That is a capital error. Then again, we hear of a man's "intellectual nature," and of his "moral nature," as if these again were divisible, and existed apart. Necessities of language do perhaps prescribe such forms of utterance; we must speak, I am aware, in that way, if we are to speak at all. But words ought not to harden into things for us. It seems to me, our apprehension of this matter is, for most part, radically falsified thereby. We ought to know withal, and to keep forever in mind, that these divisions are at bottom but names; that man's spiritual nature, the vital Force which dwells in him, is essentially one and indivisible; that what we call imagination, fancy, understanding, and so forth, are but different figures of the same Power of Insight, all indissolubly connected with each other, physiognomically related; that if we knew one of them, we might know all of them. Morality itself, what we call the moral quality of a man, what is this but another side of the one vital Force whereby he is and works? All that a man does is physiognomical of him. You may see how a man would fight, by the way in which he sings; his courage, or want of courage, is visible in the word he utters, in the opinion he has formed, no less than in the stroke he strikes. He is one; and preaches the same Self abroad in all these ways.

The moral sense, or conscience, is as much a part of man as his leg or arm. It is given to all human beings in a stronger or weaker degree, as force of members is given them in a greater or less degree. It may be strengthened by exercise, as may any particular limb of the body. This sense is submitted, indeed, in some degree, to the guidance of reason; but it is a small stock which is required for this: even a less one than what we call common sense. State a moral case to a ploughman and a professor. The former will decide it as well, and often better than the latter, because he has not been led astray by artificial rules.

Moral Philosophy is the Science of human duty. The knowledge of human duty implies a knowledge of human nature. To understand what man ought to do, it is necessary to know what man is. Not that the Moral Philosopher, before entering upon those inquiries which peculiarly belong to him, must go over the Science of human nature in all its extent. But it is necessary to examine those elements of human nature which have a direct bearing upon human conduct.

My abandonment of former beliefs was, however, never complete. Some things remained with me, and still remain: I still think that truth depends upon a relation to fact, and that facts in general are nonhuman; I still think that man is cosmically unimportant, and that a Being, if there were one, who could view the universe impartially, without the bias of here and now, would hardly mention man, except perhaps in a footnote near the end of the volume; but I no longer have the wish to thrust out human elements from regions where they belong; I have no longer the feeling that intellect is superior to sense, and that only Plato's world of ideas gives access to the 'real' world. I used to think of sense, and of thought which is built on sense, as a prison from which we can be freed by thought which is emancipated from sense. I now have no such feelings. I think of sense, and of thoughts built on sense, as windows, not as prison bars. I think that we can, however imperfectly, mirror the world, like Leibniz's monads; and I think it is the duty of the philosopher to make himself as undistorting a mirror as he can. But it is also his duty to recognize such distortions as are inevitable from our very nature. Of these, the most fundamental is that we view the world from the point of view of the here and now, not with that large impartiality which theists attribute to the Deity. To achieve such impartiality is impossible for us, but we can travel a certain distance towards it. To show the road to this end is the supreme duty of the philosopher.

The moral faculties are generally esteemed, and with justice, as of higher value than the intellectual powers. But we should always bear in mind that the activity of the mind in vividly recalling past impressions is one of the fundamental though secondary bases of conscience. This fact affords the strongest argument for educating and stimulating in all possible ways the intellectual faculties of every human being.