But, before going any farther, we must get a clear idea of what we mean by conscience. In a general way, of course, we all know what is meant by the word: an appeal to conscience would be intelligible by every one. We understand it to be a faculty which decides on a definite course of action when alternatives of good and evil are before us. We look upon it as an instinct, magnetic in its power, incessantly prompting us towards the fulfilment of duty, and gravely reproaching us on its dereliction. We recognise it as the sweetest and most troublesome of visitants; sweetest when the peace unspeakable sinks into our souls, most troublesome when we have been guilty of a great betrayal. So delicate is that voice that nothing is easier than to stifle it; so clear is it that no one by any possibility can mistake it.
Thus, in general terms, we may describe conscience. Coming now more closely to a philosophical analysis of the conception, we shall find therein much enlightenment for the purposes of our present investigation. In the first place, the word is of comparatively late origin. It does not occur in the Hebrew writers of the Old Testament. Its earliest appearance is in the Book of Wisdom, the work of a Hellenistic Jew extremely well acquainted with the trend of Greek thought in the third century B.C. It does not occur in the Gospels, except in the story of the sinful woman whom Christ refused to condemn—a history which, though profoundly in accord with the sympathetic genius of Jesus, is none the less an interpolation in the eighth chapter of the Johannine Gospel, so much so that Tischendorff excised it from his last edition of the text of the New Testament. St. Paul certainly uses the word once in the Epistle to the Romans, and though known in the latter days before the advent of Christianity, we may assume that mainly through that religion the word was popularised throughout the world.
But what is the faculty which corresponds to the word conscience? We shall find etymology of great assistance in giving precision to our thoughts. The word is, of course, a derivative from the Latin, conscientia, knowledge with, or together. Now, scientia is the simple knowledge of things by the reason, while conscientia is the knowledge which the reason has of itself; it is the realisation of one's selfhood—the realisation of the ichkeit des ego, as the very expressive German phrase has it, "the selfhood of the I". In English philosophical language we commonly denominate this self-realisation consciousness, a word of precisely the same etymological origin as conscience. If, in the next place, the reason is occupied, not with the reflex action of self-contemplation, but with moral action or the discernment of right from wrong, then it is called, and is, no longer consciousness, but conscience. Putting it technically, consciousness is a psychological expression, while conscience is ethical.
Nevertheless, it must be most carefully remembered that the two functions are performed by one and the same reason—immaterial and indivisible in us. Truly speaking, there is no real, but only a conceptual, distinction between the reason of a Darwin elaborating his famous law, realising his selfhood, and acknowledging his obligations to the eminent man—only less so than himself—who had simultaneously lighted on the great discovery of the age—the law of organic evolution. As Paul says of those manifold endowments of the earliest Christians, "A diversity of gifts and a diversity of graces, but in them all worketh the self-same spirit," so say we of the reason at the very heart of our being, the sole, self-sufficing explanation of the multitudinous phenomena of our mental life. Hence we arrive at a definition of conscience as "the practical dictate of the reason in us prescribing obedience to the good and avoidance of the evil". Two elements, therefore, are discernible in this definition: first, reason, as such, pointing out what is good and evil; and, secondly, reason, as conscience, ordaining that the good is to be done and the evil left undone—a distinction to be carefully borne in mind when the problem of conflicting consciences has to be faced; how it comes, for instance, that morality appears to differ in different countries, and even in the same individual at different periods of his life.
But of that nothing further need be said now, but we may immediately pass on to see in what sense conscience, thus explained, is, in the first place, to be accounted the voice of God.
Outside a philosophy avowedly atheist it seems difficult to understand how there can be any doubt that the eternal distinction between right and wrong betokens the presence in this world of men of a supreme power and a supreme mind. "How comes it," let us ask with Emerson, "that the universe is so constituted," that that which we instinctively recognise as good makes for the individual and the general welfare, and that which we must perforce reprobate as evil works uniformly disaster? We recognise that things are unalterably so ordered that by no possibility could lying, slander, malice and hatred be other than intrinsically evil, and their opposites be other than essentially good. But how is it that things are so ordered? Whence these uniformities of approbation and disapprobation? Is there any answer conceivable but that the power responsible for the world is a moral power? Whence is existence itself but from the subsistent source of all being? Whence is life but from one ever-lasting source? Whence is intelligence but from the world's Soul, which is the soul of men? And towering above being, above life and reason, is conscience, the supreme guide, the light enlightening every man that cometh into this world.
Luce intellettual, piena d'amore,
Amor di vero ben pien di letizia,
Letizia die trascende ogni dolzore.
What is this "light intellectual," this "love of the true," so unutterably blissful as to quiet all pain and sorrow, but the radiance of the eternal falling athwart the shadows of this lower life? What is this miraculous monitor—this "man within the breast," as the Stoics called it—but the very articulate utterance of the supreme Reason bidding man to live for the right? No great son of earth ever interpreted it otherwise. From the days when Socrates scattered "the sophist clan" in Athens, and forced men by the irresistible majesty of his own moral elevation to believe in a morality which was more than a string of rules sanctioned by convention; from the hour when he refused to escape from prison because his conscience bade him submit to die;—from the days of the sublime martyrdom of Socrates and Jesus, the noble school of the Stoics, down to the philosophic Titans of the eighteenth and nineteenth centuries in Germany, with the glorious sage of Königsberg at their head, there has been but one answer to the question, What is conscience? Conscience, they proclaimed, is the voice of God. So surely as the maternal instinct in woman is the voice of universal Nature, so surely is conscience the witness in us that we are indeed "sons of God". If that teaching of the "Over-soul" be the truth, then since the Divine is incarnate in every man, by what other voice can we be guided than by the Divine utterance commanding us to live by a moral law? We are Divine by nature, by what other law of life should we live?
Or, how are we to explain the appearance of so strange a visitant in a universe which is dominated by the "struggle for existence"? The intellectual difficulty of atheism is so insuperable that we hear of it no more from men of science. I think Mr. Spencer's speculations have given it the coup de grace. But difficult as is the question of the origin of the cosmos, far more so is that of conscience. On what principles are we to explain how a world, evolving itself mechanically, cycle after cycle, has eventually produced an element so utterly at variance with itself, an element which puts right before might, self-surrender before the struggle for existence, and the law of pity in place of the survival of the fittest? Is conscience a development of the cosmic process? And, if so, how is such a volta face in nature explicable on purely mechanical grounds, even if the process itself were so explicable? And how striking a fact that the last words Mr. Huxley[2] spoke in public should have been devoted to prove that so opposed were the cosmic and ethical processes—in other words, so completely at variance are the law of conscience and the law of evolution—that only by the triumph of the former over the latter is progress possible in the world. Again, I ask, since conscience is not the voice of Nature, of what is conscience the voice and witness if not of one of whom it is written, "In the beginning was Reason; in the beginning was Mind"?[3]
But there is another aspect of the question, and we must now pass on to inquire how far conscience is also "the voice of man commanding us to live for the right". Quite at the beginning of this ethical movement we protested, as plainly as words would allow, our entire allegiance to the teachings of physical science, and our readiness to abandon any doctrine of ethical religion which is disproved by experimental research. So convinced are we of the absolute unity of truth, because with Plato we believe in the unity of its source in the Divine intelligence, that to us it is inconceivable that there should be any fundamental contradiction in the orders of the real and the ideal. Things seen and unseen, the passing and the eternal, both ultimately take their origin in the same source, the Infinite. No finite thing can be the ultimate explanation of the universe, because it itself requires explanation. Hence, whatever science has to tell us about conscience will be enthusiastically acclaimed by us as true equally with what we learn from the masters of the higher experience, the philosophers who break unto us the bread of life.