153. The influences commonly pointed out as instrumental in bringing about the recognition of rights in the man, as independent of particular citizenship, are these: (1) The adjudication by Roman praetors of questions at issue between citizens and those who were not so, which led to the formation of the system of 'equity,' independent of the old civil law and tending gradually to be substituted for it. The existence of such a system, however, presupposes the recognition of rights so far independent of citizenship in a particular state as to obtain between citizens of different states. (2) The doctrine of a 'law of nature' applicable to dealings of all men, popularised by the Stoics. (3) The Christian conception of the universal redemption of a brotherhood, of which all could become members through a mental act within the power of all. 154. The admission of a right to free life on the part of every man, as man, does in fact logically imply the conception of all men as forming one society in which each individual has some service to render, one organism in which each has a function to fulfil. There can be no claim on society such as constitutes a right, except in respect of a capacity freely (i.e. under determination by conception of the good) to contribute to its good. If the claim is made on behalf of any and every human being, it must be a claim on human society as a whole, and there must be a possible common good of human society as a whole, conceivable as independent of the special conditions of particular societies, to render such a claim possible. We often find, however, that men assimilate a practical idea in respect of one of its implications without doing so in respect of the rest. Thus the idea of the individual's right to free life has been strongly laid hold of in Christendom in what may be called an abstract or negative way, but little notice has been taken of what it involves. Slavery is everywhere condemned. It is established that no one has a right to prevent the individual from determining the conditions of his own life. We treat life as sacred even in the human embryo, and even in hopeless idiots and lunatics recognise a right to live, a recognition which can only be rationally explained on either or both of two grounds: (1) that we do not consider either their lives, or the society which a man may freely serve, to be limited to this earth, and thus ascribe to them a right to live on the strength of a social capacity which under other conditions may become what it is not here; or (2) that the distinction between curable and incurable, between complete and incomplete, social incapacity is so indefinite that we cannot in any case safely assume it to be such as to extinguish the right to live. Or perhaps it may be argued that even in cases where the incapacity is ascertainably incurable, the patient has still a social function (as undoubtedly those who are incurably ill in other ways have), a passive function as the object