19. The question before us, then, is, In what ways and how far do the main obligations enforced and rights maintained by law in all civilised societies contribute to the moral end described; viz. to establish those conditions of life in which a true, i.e. a disinterested or unselfish morality shall be possible? The answer to this question will be a theory of the 'jus naturae'; i.e. it will explain how far positive law is what it should be, and what is the ground of the duty to obey it; in other words, of political obligation. There are two things from which such a theory must be distinguished. (1) It is not an inquiry into the process by which actual law came to be what it is; nor (2) is it an inquiry how far actual law corresponds to and is derived from the exercise of certain original or natural rights. (1) It is not the former, because the process by which the law of any nation and the law in which civilised nations agree has come to be what it is, has not been determined by reference to that end to which we hold that law ought to be directed and by reference to which we criticise it. That is to say, the process has not been determined by any such conscious reference on the part of the agents in the process. No doubt a desire for social good as distinct from private pleasure, for what is good on the whole as distinct from what is good for the moment, has been a necessary condition of it; but _(a)_, as an agent in the development of law, this has not reached the form of a conception of moral good according to that definition of it by which the value of law is to be estimated; and _(b)_ in bringing law to its present state it has been indistinguishably blended with purely selfish passions and with the simple struggle for existence. 20. (2) A true theory of 'jus naturae,' a rationale of law or ideal of what it should be, is not to be had by inquiring how far actual law corresponds to, and is derived from, the exercise of certain original or natural rights, if that is taken to mean that we know, or can ascertain, what rights are natural on grounds distinct from those on which we determine what laws are justifiable, and that then we can proceed to ascertain what laws are justifiable by deduction from such rights. 'Natural rights,' so far as there are such things, are themselves relative to the moral end to which perfect law is relative. A law is not good because it enforces 'natural rights,' but because it contributes to the realisation of a certain end. We only discover what rights are natural by considering what powers must be secured to a man in order to the attainment of this end. These powers a perfect law will secure to their full extent. Thus the consideration of what rights are 'natural' (in the only legitimate sense) and the consideration what laws are justifiable form one and the same process, each presupposing a conception of the moral vocation of man.