Ethics is that branch of philosophy which is concerned with human character and conduct. It deals with man as a source of action, and not merely as the subject of knowledge. It is thus brought into the closest relation with psychology, which explains the nature and origin of the mental processes of the individual, and with the investigations into the development of human instincts and institutions made by the new science of sociology. In this way a number of questions arise which are in their terms psychological or sociological, although they have nearly always been discussed with a view to their ethical bearing. Such are (1) the psychological question concerning the way in which ethical or moral principles are apprehended—the question of Conscience or the moral faculty; (2) a series of inter-connected psychological questions concerning the motives to action, or the way in which morality is realised in conduct—e.g. (a) whether reason can be a motive to action—the question of the relation of Reason to Sentiment, (b) whether motives can be reduced to a common formula in terms of pleasure and pain—the question of the relation of Pleasure to Desire, (c) whether and how far spontaneity is involved in voluntary action—the time-honoured question of Free-will; (3) a psychological question as to the way in which character is moralised—the question of the nature and relation of the Virtues. Besides these, there is (4) the historical question of the connection of moral ideas and practice with the social customs of the time, and its political, religious, and other institutions.
The preceding questions all deal with the actual facts of conduct and character—their order and historical connection. But it is characteristic of properly ethical inquiry to seek to determine the principles or end by which conduct is to be regulated. Ethics thus looks at things from a point of view foreign to the theoretical sciences. It has to do not merely with what is, but with what ought to be. This is indicated by the familiar opposition between Right and Wrong in conduct, Virtuous and Vicious in character, and in the notion of Duty, in which the human will is conceived as under an obligation to obey a certain law, or follow a certain end, which obligation, however, may or may not be fulfilled in actual conduct. This notion of moral obligation or Duty does not come to the front in the Greek philosophers, to whom the origin of our philosophical conceptions of morality is mainly due. Its present fullness of signification is largely due to legal and to religious modes of thought; and, owing to its influence, modern ethics has frequently received a distinctly legal or theological stamp—being represented as a system of duties, prescribed by God, or by Conscience, in which certain kinds of action are enjoined and others forbidden. But, underlying this notion, there is the conception of certain kinds of conduct, or certain types of character, as better than others, or preferable to them. This, at least, is involved in all ethical thought. And the attempt to reach a synthesis of what is called morally good, or to give a reason for preferring certain objects to others, necessarily leads to the inquiry after an ultimate end, which is not desired as a means to anything else, but is held to be good in itself. This is the ethical end, or Chief Good, which formed the leading subject of discussion in Greek ethics, and to the explicit investigation of which modern ethical speculation has to a large extent returned.
The nature of this chief good has been differently defined by different schools. But it was remarked by Aristotle, at a time when ethical terminology was less complex than it is now, that, in spite of their different views as to the nature of this good, all men are agreed as to its name: calling it eudaimonia—a term equivalent to 'well-being', but unfortunately rendered, according to the universal tradition of translators, by the English word happiness. The word happiness in modern ethical discussions signifies a maximum of pleasures, or an experience in which the pleasures greatly exceed the pains. In this sense of the word, however, the assertion that the good is happiness would have been denied by Aristotle, as well as by Plato. While arguing that the good for man must be something obtainable by man, Aristotle did not find the end in pleasure, but rather in the perfect development of a man's self, in moral and intellectual excellence. But the doctrine that pleasure is the highest good was held by predecessors and contemporaries of Aristotle, and was afterwards formulated by Epicurus into an ethical theory.
This view that pleasure or happiness is the chief good has been held in two very different forms. According to the one view, the chief good and moral end for each individual is his own happiness or pleasure; according to the other view, it is the happiness or pleasure of the community, or of mankind, or even of sentient creatures generally. The former was the doctrine of Epicurus, and has been called Egoistic Hedonism. The latter view—called Universalistic Hedonism or Utilitarianism—owes its development to modern and especially to English writers. A principle similar to that of modern utilitarianism was laid down very early in the history of English ethics. Thus, it has been pointed out that Richard Cumberland, in his treatise De legibus Naturæ (1672), put forward the 'common good of all' as the supreme end to which all rules of conduct are subordinate, though, according to him, this good includes perfection as well as happiness. In a similar way, Shaftesbury (Inquiry concerning Virtue and Merit, 1699), Joseph Butler (in his Sermons, 1726), and Francis Hutcheson (System of Moral Philosophy, 1755) speak of the 'good of society' as equivalent to virtue. But the real founder of modern utilitarianism was David Hume (Treatise of Human Nature, 1739; Inquiry into the Principles of Morals, 1751). He defined Virtue as a quality approved by the spectator, and Vice as a quality blamed or censured by the spectator, and endeavoured to show, by a review of the virtues, that the qualities approved are either immediately agreeable or useful (i.e. indirectly agreeable) to ourselves or to others. In this way, utility is made the ground of the distinction between Virtue and Vice. The Moral Philosophy of Paley (1785) contributed largely to define and render applicable to practice the utilitarian criterion of morality; though, in his system, the utilitarian principle is based upon an 'other-worldly' selfishness. Subsequently, utilitarianism was defended and applied to morals, politics, and law by Jeremy Bentham (1748–1832), who was surrounded by an energetic school of writers, including Ricardo, James Mill, J. S. Mill, Austin, and George Grote. J. S. Mill's remarkable essay on Utilitarianism (1861) is chiefly occupied with defending the theory against the popular objections to it, which had been increased rather than obviated by Bentham's uncompromising polemics. He especially contended against the representation of utilitarianism as a selfish and a sensual theory. It is not selfish (he argued), for it requires that a man should be impartial in deciding between his own interests and those of others. It is not sensual, for man possesses faculties of a kind which sensual pleasures cannot satisfy. The being of lower faculties may have more contentment, because without the desire for anything further, but has not more pleasure or happiness. In defending this position Mill does not rely merely on the greater permanence, purity, and fruitfulness of the intellectual and social pleasures as compared with the pleasures of sense. He asserts that pleasures differ from one another in kind as well as in degree or intensity, and that the pleasure of higher quality or kind is to be preferred to one of lower quality, even although the intensity of the latter be greater than that of the former. It is now, however, generally admitted that this distinction is inconsistent with the hedonistic basis of utilitarian ethics, seeing that it makes not the pleasure itself, but that which distinguishes one pleasure from another, the real ground of moral preference.
Owing to the definiteness of its principle, and the facility (within a certain range) with which it can be applied, the utilitarian maxim admitted, in the hands of Bentham and his school, of fruitful application to political and legal questions. The proof, or philosophical basis, of the theory presents greater difficulty. Pleasure, indeed, may be obviously desirable, though it is not so obvious that it is the ultimate or highest moral end. But it is plainly due to confusion of thought that this desirableness of pleasure is given (by J. S. Mill) as a sufficient reason for holding that the general happiness is the ethical end for the individual. The gulf between egoistic hedonism and utilitarianism requires to be bridged over. The transition from one position to the other has frequently been made by the help of religious or of political considerations. Thus the utilitarianism of Paley was founded on the belief that the happiness of mankind was the ethical end prescribed by God; that of Bentham resulted from looking at action from the point of view of the community and its interests rather than from that of the interests of the individual. In this connection, consideration is given to the sanctions of morality, or pains following the breach of moral law. These sanctions are enumerated as religious, political, social, and internal. The religious sanction is that relied on by Paley. Bentham and Mill lay greater stress on the others. But it is admitted that the political sanction does not exact from an individual beneficence, or active regard to his neighbour's happiness, but only probity, or non-interference with that happiness. The social sanctions, again, are incomplete and variable, and have no exact correspondence with the utilitarian principle; while the internal sanctions depend on the individual conscience, which utilitarian writers commonly hold to be a growth in the individual mind, due to and imitating the social sanctions. The unsatisfactoriness of the proof of utilitarianism is recognised in the chief recent exposition of the theory—that in Sidgwick's Methods of Ethics (1874). The utilitarian theory of the moral end or standard is there associated with an intuitive theory of knowledge not usually held by utilitarians: the justification of the theory is based on the axioms of justice and benevolence, which the exhaustive examination of intuitive ethics carried out in the same work has left standing as formal axioms of the practical reason. Owing to the influence of the doctrine of evolution as applied to character, a still more radical transformation has been effected in the utilitarian theory (Spencer's Data of Ethics, 1879; L. Stephen's Science of Ethics, 1882). Applied only to the method of utilitarianism in Spencer's hands, the evolution-theory has been used by other writers to show the inadequacy of the utilitarian principle; but few attempts have been made to substitute for the latter an ideal in better correspondence with the facts and laws of moral development.
Utilitarianism is a morality of consequences: finding the moral quality of conduct and character in the kind of feeling actions tend to produce in sentient beings. As this pleasant or painful feeling can only be ascertained by experience, the theory is nearly always associated with an empirical theory of the origin of our knowledge of morality. The controversies, especially of English ethics, have been largely occupied with the debate on this question between the Empirical and Intuitive schools of ethics. The latter school lays stress on the immediateness and universality of the moral judgments passed by each man's conscience. A doctrine of the Moral Sense, as a feeling, or perception, by which actions or motives were morally distinguished apart from their consequences, was developed by Shaftesbury and Hutcheson; and Butler formulated the doctrine that conscience is the supreme authority as to what is right or wrong. It is true that in Butler's Sermons Self-love, or a calm regard to one's interests on the whole, is frequently spoken of as co-ordinate with, and indeed, in one place, as superior to Conscience. But this is inconsistent with Butler's explicit statements even in that work, and the view does not reappear in the Dissertation on Virtue appended to the Analogy (1736). In the latter work, also, the virtuous action which conscience prescribes is no longer asserted to be conterminous with action aiming at the good or happiness of society. In this way Butler's severance from utilitarianism is complete, and he may be fitly regarded as the head of the modern intuitive school. Of this school Dr Martineau (Types of Ethical Theory, 1885) is a prominent representative; differing, however, from the majority of the school in holding that moral quality belongs primarily to motives, not to action. The weakness of the intuitive position, as stated by Butler and many of his successors, lies in the fact that the source of ethical principles, conscience, is not brought into intelligible relation with the rational or spiritual nature of man. Hence the force of the objection urged against Butler—that he moves in a circle, defining the right as what conscience approves, and conscience as what approves the right. The doctrine of Conscience holds an insecure position in his system, because it is unrelated to reason, because, in a word, his ethics is without foundation in metaphysics. On this account, the position has been peculiarly liable to be undermined by empirical analyses, such as Bain's attempt (The Emotions and the Will, 1859; Mental and Moral Science, 1868) to trace the growth of conscience in the individual from fear and love with a perception of utility added, or the more elaborate efforts of evolutionist writers, by whom it is represented as the result of countless experiences of the effects of action transmitted from individual to individual, until, in the form of a moral sense or conscience, they have become part of the common mental inheritance of the race. A further difficulty connected with the view of conscience held by Intuitionists is the mutual relation of the kinds of actions it approves, or of the laws for action laid down by it. Justice, veracity, beneficence, &c. are said to be its laws; but the attempt is seldom made to show how these are connected with one another.
These obvious difficulties meet at least with an attempted solution in the ethical system of Kant (Groundwork of the Metaphysic of Morals, 1785; Critique of Practical Reason, 1788). For Kant, conscience is simply practical reason; and its laws are reduced to unity. Reason, although limited in its knowledge of objects to the phenomena of sense, is yet in the practical sphere capable of laying down absolute or unconditional laws. This is shown by the moral law, with its categorical 'thou shalt,' prescribing a principle of conduct irrespective of desire or any ulterior end. Only the action which proceeds from a good will (that is, a will in accordance with moral law) is completely good. External conformity to the law gives legality; morality requires that the law, or respect for it, should be the moving principle of action. This, according to Kant, may prove to us that the will is free: 'thou shalt' implies 'thou canst.' Thus, in the order of our knowledge, it is the moral law that convinces us of freedom. But in reality the moral law is simply the law of the will itself, and the will is free when acting under its own law; it is under constraint only when influenced by the sensuous nature with which it is connected in man. The 'categorical imperative' of the moral law is expressed by Kant in the phrase, 'Act according to that maxim (or subjective principle) alone which thou canst at the same time will to be a universal law.' Reason is one in all men, and action to be rational must thus admit of being universalised. In this way reason gives a form for action. It also gives its end; for reason is an end in itself, and humanity, as rational, must therefore always be treated as an end, never as a mere means. Kant's ethical principle remains, however, a formal principle, not admitting of the connection he sought to give it with the content of practical life. Its formality or emptiness is due to his purely formal conception of reason itself. To get rid of this formality has been the effort of the later ethical systems which have been most influenced by Kant. They base morality, as he did, on the reason or spiritual principle; but, with a less restricted view of this principle, they seek its content and realisation in practical life and its institutions. This position, largely due to Hegel, has been worked out independently in the most important recent English work of speculative ethics—T. H. Green's Prolegomena to Ethics (1883). 'The ultimate standard of worth is,' according to Green, 'an ideal of personal worth,' while, at the same time, 'it is equally true that the human spirit can only realise itself, or fulfil its idea, in persons, and that it can only do this through society, since society is the condition of the development of a personality.' It thus appears that at the present time the two leading ethical schools in Britain may both be called evolutionist—the one, that just described, looking upon morality as the gradual realisation of a spiritual principle in the forms and institutions of domestic, civic, and political life; the other holding that the evolution is a merely natural one, and giving the name morality to those habits of acting which have contributed to the preservation and development of the race. The former theory is connected historically with intuitionism, the latter with utilitarianism. Neither is able to give so precise a definition of the moral ideal as was attempted by the older theories; and it may be admitted, perhaps consistently, by both sides (though with some difference of meaning under the similarity of phrase), that no such precise definition is possible, but that our apprehension of the ideal itself becomes clearer and fuller as it is progressively realised in the individual life and in society.
Some of the more important ethical writings, of different schools, have been already mentioned. The best introduction to the history of the subject is Sidgwick's Outlines of the History of Ethics for English Readers (1886). See articles on the great ethical thinkers, ARISTOTLE, EPICURUS, STOICS, BUTLER, KANT, &c.; also EVOLUTION.