§1. In the last chapter I have spoken of Ethics and Politics as being both Practical Studies, including in the scope of their investigation somewhat that lies outside the sphere of positive sciences---viz. the determination of ends to be sought, or rules to be unconditionally obeyed. Before proceeding further, it would seem desirable to determine in outline the mutual relations of these cognate studies, regarded from the point of view of Ethics.
As I have defined them, Ethics aims at determining what ought to be done by individuals, while Politics aims at determining what the government of a state or political society ought to do and how it ought to be constituted,---including under the latter head all questions as to the control over government that should be exercised by the governed.
At first sight it may seem that Politics, so conceived, must be a branch of Ethics. For all the actions of government are actions of individuals, alone or in combination, and so are all the actions of those who, obeying, influencing, or perhaps occasionally resisting government, maintain and from time to time modify the constitution of their state: and it would seem that if properly performed such actions must be determined on ethical principles or be capable of justification by such principles. But this argument is not decisive; for by similar reasoning Ethics would have to comprehend all arts, liberal and industrial. E.g. it is a main part of the moral duty of a sea-captain and his subordinates to navigate their ship properly; but we do not take Ethics to include a study of the rules of navigation. It may be replied that every man is not a sailor, but---at least in a country under popular government---every citizen has important political duties, which he ought to perform according to knowledge, sop far as possible; but, similarly, it is an important part of every adult's moral duty to take care of his health, and it is proverbial that ``every man at forty is a fool or his own physician''; yet we do not consider Ethics to include the art of medicine.
The specially important connexion between Ethics and Politics arises in a different way. It is the business of government, by laying down and enforcing laws, to regulate the outward conduct of the governed, not in one department only, but in all their social relations, so far as such conduct is a proper subject for coercive rules. And not only ought this regulation to be in harmony with morality---for obviously people ought not to be compelled to do what they ought not to do---but further, to an important extent the Law of a man's state will properly determine the details of his moral duty, even beyond the sphere of legal enforcement. Thus we commonly regard it as an individual's moral duty, under the head of Justice, to ``give every man his own'', even when---through some accident---the other party has not the power of legally enforcing his right; but still, in considering what is the other's ``own'', we assume him generally to be guided by the law of his state; if that were changed, his moral duty would change with it. Similarly, the mutual moral duties of husbands and wives, and of children and parents, will vary in detail with the variations in their legal relations.
But when we look closer at the relation thus constituted between Ethics and Politics, we see that a distinction has to be taken between actual or Positive Law and Ideal Law or Law as it ought to be. It is for the latter that Political Theory lays down principles; but it is Positive, not Ideal, Law that primarily determines right conduct for an individual here and now, in the manner just exemplified. No doubt if Positive and Ideal Law appear to me to diverge very widely---if (e.g.) I am convinced by political theory that a fundamental change in the law of property is desirable---this conviction is likely to influence my view of my moral duty under the existing law; but the extent of this influence is vague and uncertain. Suppose I am a slave-owner in a society in which slavery is established, and become convinced that private property in human beings should be abolished by law: it does not therefore follow that I shall regard it as my moral duty to set free my slaves at once. I may think immediate general abolition of slavery not only hopeless, but even inexpedient for the slaves themselves, who require a gradual education for freedom: so that it is better for the present to aim at legal changes that would cut off the worst evils of slavery, and meanwhile to set an example of humane and considerate treatment of bondsmen. Similar reasonings might be applied to the abolition of private property in the instruments of production, or in appointments to offices, civil or ecclesiastical. Speaking generally, the extent to which political ideals ought to influence moral duty would seem to depend partly on the apparent remoteness or nearness of the prospect of realising the ideal, partly on its imperativeness, or the expediency of immediate realisation: and the force attached to both these considerations is likely to vary with the political method adopted; so that it belongs to Politics rather than Ethics to determine them more precisely.
To sum up: we have to distinguish clearly between two questions: (1) how far the determination of right conduct for an individual here and now ought to be influenced by Positive Laws, and other commands of Government as actually established; and (2) how far it ought to be influenced by Political Theory, as to the functions and structure of Government as it ought to be. As regards the former, it clearly belongs to Ethics to determine the grounds and limits of obedience to Government; and also the general conception of political duty, so far as it goes beyond mere obedience-with due recognition of the large variations due to the varying political conditions of different states. (A ``good citizen'' in the United States will reasonably form a conception of his actual political duty widely divergent from that reasonably formed by a good citizen in Russia.) And this will be the primary business of Ethics so far as it deals with the political side of life. The discussion of political ideals will only come within its purview in a more indefinite and indirect way, so far as such ideals cannot but have some influence on the determination of political duty under existing conditions.