A writer who seeks to gain general confidence scarcely goes the right way to work when he begins with asking whether there really is such a subject of that of which he proposes to treat; whether it is one to which enquiry can be directed with any prospect of a valuable result. Yet to a writer on Moral Philosophy such a mode of procedure is prescribed, not only by the logical impulse to begin at the beginning, but by observation of the prevalent opinions around him. He can scarcely but be aware that Moral Philosophy is a name of somewhat equivocal repute; that it commands less respect among us than was probably the case a century ago; and that any one who professes to teach or write upon a subject to which this name is in any proper or distinctive sense applicable, is looked upon with some suspicion. (§1 ¶1)

There is, indeed, no lack of utterance in regard to the greatest problems of life or the rights and wrongs of human conduct. Nor does it by any means confine itself to what are commonly counted secular or positive considerations. Glosses as to some sweet strange mystery,
Of what beyond these things may lie,
And yet remain unseen, are announced with little reserve and meet with ready acceptance. These, we may say, are for the multitude of the educated, who have wearied of the formulas of a stereotyped theology, but still demand free indulgence for the appetite which that theology supplied with a regulation-diet. But the highest poetry of our time—that in which the most serious and select spirits find their food—depends chiefly for its interest on what has been well called the application of ideas to life; and the ideas so applied are by no means sensibly verifiable. They belong as little to the domain of natural science, strictly so called, as to that of dogmatic theology. A moral philosopher may be excused for finding much excellent philosophy, in his special sense of the word, in such poems as the In Memoriam of Lord Tennyson and Mr. Browning’s Rabbi ben Ezra, to say nothing of the more explicitly ethical poetry of Wordsworth. Presented in the rapt unreasoned form of poetic utterance, not professing to do more than represent a mood of the individual poet, it is welcomed by reflecting men as expressing deep convictions of their own. Such men seem little disturbed by the admission to a joint lodgement in their minds of inferences from popularised science, which do not admit of being reconciled with those deeper convictions in any logical system of beliefs. (§1 ¶2)

But if any one, alarmed at this dangerous juxtaposition, and unwilling that what seem to him the deepest and truest views of life should be retained merely on scientific sufferance, seeks to find for them some independent justification, in the shape of a philosophy which does not profess to be a branch either of dogmatic theology or of natural science, he must look for little thanks for his trouble. The most intelligent critics had rather, it would seem, that the ideas which poetry applies to life, together with those which form the basis of practical religion, should be left to take their chance alongside of seemingly incompatible scientific beliefs, than that anything calling itself philosophy should seek to systematise them and to ascertain the regions to which they on the one side, and the truths of science on the other, are respectively applicable. Poetry we feel, science we understand;—such will be the reflection, spoken or unspoken, of most cultivated men;—theology professes to found itself on divine revelation, and has at all events a sphere of its own in the interpretation of sacred writings which entitles it at least to respectful recognition; but this philosophy, which is neither poetry nor science nor theology, what is it but a confusion of all these in which each of them is spoilt? Poetry has a truth of its own, and so has religion—a truth which we feel, though from the scientific point of view we may admit it to be an illusion. Philosophy is from the scientific point of view equally an illusion, and has no truth that we can feel. Better to trust poetry and religion to the hold which, however illusive, they will always have on the human heart, than seek to explain and vindicate them, as against science, by help of a philosophy which is itself not only an illusion but a dull and pretentious one, with no interest for the imagination and no power over the heart. (§1 ¶5)

There were two elements, indeed, in the system of popular ethics inherited from the last century, which were long thought incompatible with its complete reduction to the form of a physical science. These were the doctrines of free-will and of a moral sense. Each, however, was understood in a way which suggested to the naturalist a ready explanation of its supposed claim to lie beyond his sphere. The moral sense, according to the accepted view, was a specific susceptibility to pleasure or pain in the contemplation of certain acts. What was the quality in the acts which excited this pleasure or pain in the contemplation of them? If it were something in the conception of which any originative function of the reason was implied, then the existence of the moral sense would have meant that there was a determining agent in the inner life of man, of which no natural history could be given. But those writers who had made most of the moral sense had been very indefinite in their account of the quality in action to which it was relative. The most consistent theory on the subject was Hume’s. According to him the pleasure of moral sense is pleasure felt in the mere survey of an act, independently of any consequences of the act to the person contemplating it; and that which occasions this pleasure is the tendency of the act to bring pleasure to the agent himself or to others. Moral sense, in short, is a social sentiment either of satisfaction in the view of such conduct as has been generally found to increase the pleasure or diminish the pain of others, or of uneasiness in the reverse, quite apart from any expectation of personal advantage or loss. It is thus properly not by the action of the person feeling it, but by that of others, that it is excited. An act of a man’s own, necessarily proceeding, according to Hume, from some desire for pleasure which it satisfies or fails to satisfy, must have personal consequences for him, incompatible with that disinterested survey which alone yields the pleasure or pain of moral sense, properly so called. Sympathy, however, with the effect which he knows that his act produces on the moral sense of others, may modify the feeling which it causes to the doer of it. An act, in gratification of some passion, which he would otherwise look forward to as pleasant, may become so painful in anticipation from sympathy with the general uneasiness which he knows would arise upon the contemplation of it that, without any fear of punishment, he abstains from doing it. (§3 ¶1)

Thus moral sense and sympathy jointly, as understood by Hume, serve plausibly to explain the office ordinarily ascribed to conscience, as the judge and possible controller in each man of his own acts. At the same time the lines are indicated along which a physical theory of conscience might be logically attempted. The problem which Hume bequeathed to a successor who adopted his principles was mainly to account for the twofold fact, that the mere survey of actions as tending to produce pleasures in which the contemplator will have no share, is yet a source of pleasure to him; and that, among the pleasures taken into account in that estimate of the tendency of an action which determines the moral sentiment, are such as have no direct connexion with the satisfaction of animal wants. A theory which will account for this will also account for the affection of the agent by sympathy with the sentiment which the contemplation of his action excites in others. Can we find any scientific warrant for believing in a process by which, out of susceptibility to pleasure incidental to the merely animal life, there have grown those capacities for enjoyment which we consider essential to general well-being, and those social interests which not only make the contemplation of general well-being an independent source of pleasure, but also make the pleasure of exciting this pleasure—the pleasure of satisfying the moral sentiment of others—an object of desire so strong as in many cases to determine action? If we can, it would seem that we have given to our national system of ethics—the ethics of moral sentiment—the solid foundation of a natural science. (§4 ¶1)

It is no wonder, therefore, that the evolutionists of our day should claim to have given a wholly new character to ethical enquiries. In Hume’s time a philosopher who denied the innateness of moral sentiments, and held that they must have a natural history, had only the limits of the individual life within which to trace this history. These limits did not give room enough for even a plausible derivation of moral interests from animal wants. It is otherwise when the history may be supposed to range over an indefinite number of generations. The doctrine of hereditary transmission, it is held, explains to us how susceptibilities of pleasure and pain, of desire and aversion, of hope and fear, may be handed down with gradually accumulated modifications which in time attain the full measure of the difference between the moral man and the greater ape. Through long ages of interaction between the human organism and the social medium in which it lives, there has been developed that sensibility of principle which feels a stain like a wound; that faculty of moral intuition which not only pronounces unerringly on the social tendencies of the commonest forms of human action, but enables us in some measure to see ourselves as others see us; that civil spirit through which the promptings of personal passion are controlled even in the individual by the larger vision and calmer interest of society. (§5 ¶1)

Thus it would seem that for the barren speculation of the old metaphysical ethics we should seek a substitute in a scientific Culturgeschichte; in a natural history of man conducted on the same method as an enquiry into any other form of life which cannot be reduced to the operation of strictly mechanical laws. For the later stages of this history we have, of course, abundant materials in the actual monuments of human culture—linguistic, literary, and legal—and these, the physiologist may say, have yet to be considered in connexion with the data which his own science furnishes. It is true that, however far they carry us back, however great the variations of moral sentiment to which they testify, they do not bring us to a state of things in which the essential conditions of that sentiment were absent. The most primitive man they may exhibit to us is already conscious of his own good as conditioned by that of others, alrseady capable of recognising an obligation. But the theory of descent and evolution opens up a vista of possibilities beyond the facts, so far ascertained, of human history, and suggests an enquiry into the antecedents of the moralised man based on other data than the records which he has left of himself. Such enquiry, it is thought, will in time give us the means of reducing the moral susceptibilities of man to the rank of ordinary physical facts, parts of one system, and intelligible by the same methods, with all the natural phenomena which we are learning to know. Man will then have his ascertained place in nature, as perhaps the noblest of the animals, but an animal still. (§5 ¶2)

When the moral sentiment has been explained on the principles of natural science, free-will is not likely to be regarded as presenting any serious obstacle to the same mode of treatment. By those of our national philosophers who have asserted its existence, it has generally been understood as a faculty of determining action apart from determination by motives; as a power, distinct alike from reason and from desire, which chooses between motives without itself being dependent on any motive. So crude a notion must long ago have given way before the questons of science, if there had not been a practical conviction behind it which it failed fairly to interpret. What after all, it is asked, is any faculty but an hypostatised abstraction? A faculty is no more than a possibility. Whatever happens implies no doubt a possibility of its happening. Voluntary action implies a possibility of voluntary action, just as the motion of a billiard-ball implies a possibility of that motion; but the possibility in each is determined by definite conditions. In the case of the billiard-ball these conditions, or some of them, are so obvious that we do not think of treating the possibility of the ball’s moving as a faculty inherent in the ball, and of sacrificing the ball’s motion to this faculty as its cause; although, as we know, when the causes of a motion are less apparent, the uninstructed are quite ready to ascribe it to a faculty or power in the moving body. In ascribing any voluntary action to a faculty in man, we are doing, it is said, just the same as in ascribing any particular motion to a faculty in the moving body. The fact is the particular voluntary action, which must be possible, no doubt, or it would not be done, but of which the real possibility consists in the assemblage of conditions which make up its cause. To include any faculty of action among these is merely to express our ignoranceof what they are or our unwillingness to examine them. Among them, it is true, is the wish which happens to be predominant in the agent at the moment of action; but this, too, has its definite conditions in the circumstances of the case and the motives operating on the agent. It may be owing to the character of the agent that one of these motives gets the upper hand; but his character again is only a name for an assemblage of conditions, of which it may be scarcely possible for us to completely trace the antecedents, but which we are not on that account justified in assigning to a cause that is no cause, but merely a verbal substantiation of the abstraction of our ignorance. Human freedom must be understood in some different sense from that with which our anthropologists are familiar, if it is to stand in the way of the scientific impulse to naturalise the moral man. (§6 ¶1)

We will suppose then that a theory has been formed which professes to explain, on the method of a natural history conducted according to the principle of evolution, the process by which the human animal has come, according to the terminology in vogue, to exhibit the phenomena of a moral life—to have a conscience, to feel remorse, to pursue ideals, to be capable of education through appeals to the sense of honour and of shame, to be conscious of antagonism between the common and the private good, and even sometimes to prefer the former. It has generally been expected of a moralist, however, that he should explain not only how men do act, but how they should act: and as a matter of fact we find that those who regard the process of man’s natural development most strictly as a merely natural one are as forward as any to propound rules of living, to which they conceive that, according to their view of the influences which make him what he is, man ought to conform. The natural science of man is to them the basis of a practical art. They seek to discover what are the laws—the modes of operation of natural forces—under which we have come to be what we are, in order that they may counsel us how to seek our happiness by living according to those laws. (§7 ¶1)

Now it is obvious that to a being who is simply a result of natural forces an injunction to conform to their laws is unmeaning. It implies that there is something in him independent of those forces, which ma determine the relation in which he shall stand to them. A philosopher, then, who would reconstruct our ethical systems in conformity with the doctrines of evolution and descent, if he would be consistent, must deal less scrupulously with them than perhaps any one has yet been found to do. If he has the courage of his principles, having reduced the speculative part of them to a natural science, he must abolish the practical or preceptive part altogether. Instead, for instance, of telling men of a greatest sum of pleasures which they ought to seek, and which by acting in the light of a true insight into natural laws they may attain, he will content himself with ascertaining, so far as he can, whether such and such a temperament under such and such circumstances yields more frequent, durable, and intense pleasures than such another temperament under such other circumstances. He will not mock the misery of him who fails, nor flatter the self-complacency of him who prospers, by speaking of a happiness that is to be obtained by conformity to the laws of nature, when he knows that, according to his own principles, it is a struggle for existence determined by those laws which has brought the one to his wretchedness and the other to his contentment. He will rather set himself to show how the phraseology of ought and ought not, the belief in a good attainable by all, the consciousness of something that should be though it is not, may according to his philosophy be accounted for. Nor, if he has persuaded himself that the human consciousness, as it is, can be physically accounted for, will he find any further difficulty in thus explaining that language of moral injunction which forms so large an element in its expression. He will probably trace this language to the joint action of two factors—to the habit of submission to the commands of a physical or political superior, surviving the commands themselves and the memory of them, combined with that constant though ineffectual wish for a condition of life other than his own, which is natural to a being who looks before and after over perpetual alternations of pleasure and pain. (§7 ¶2)

The elimination of ethics, then, as a system of precepts, involves no intrinsic difficulties other than those involved in the admission of a natural science that can account for the moralisation of man. The discovery, however, that our assertions of moral obligation are merely the expression of an ineffectual wish to be better off than we are, or are due to the survival of habits originally enforced by physical fear, but of which the origin is forgotten, is of a kind to give us pause. It logically carries with it the conclusion, however the conclusion may be disguised, that, in inciting ourselves or others to do anything because it ought to be done, we are at best making use of a serviceable illusion. And when this consequence is found to follow logically from the conception of man as in his moral attributes a subject of natural science, it may lead to a reconsideration of a doctrine which would otherwise have been taken for granted as the most important outcome of modern enlightenment. As the first charm of accounting for what has previously seemed the mystery of our moral ature passes away, and the spirit of criticism returns, we cannot but enquire whether a being that was merely a result of natural forces could form a theory of those forces as explaining himself. We have to return once more to that analysis of the conditions of knowledge, which forms the basis of all Critical Philosophy whether called by the name of Kant or no, and to ask whether the experience of connected matters of fact, which in its methodical expression we call science, does not presuppose a principle which is not itself any one or number of such matters of fact, or their result. (§8 ¶1)

Can the knowledge of nature be itself a part or product of nature, in that sense of nature in which it is said to be an object of knowledge? This is our first quesiton. If it is answered in the negative, we shall at least have satisfied ourselves that man, in respect of the function called knowledge, is not merely a child of nature. We shall have ascertained the presence in him of a principle not natural, and a specific function of this principle in rendering knowledge possible. The way will then be so far cleared for the further question which leads us, in the language of Kant, from the Critique of Speculative to that of Practical Reason: the question whether the same principle has not another expression than that which appears in the determination of experience and through it in our knowledge of a world—an expression which consists in the consciousness of a moral ideal and the determination of human action thereby. (§8 ¶2)