490 HARVARD LAW REVIEW. Reciprocity, then, is a law of obligation which creates ethical relations between two or more persons, or between persons and society. These relations may be regarded from the point of view of either term. From one aspect they are usually called obliga- tions, and from the other rights. The two words are thus but antithetical names for one and the same relation. In the self- regarding or egoistic aspect the relation concerns the free self- development of each member of society. To interfere with that is a breach of the obligation of reciprocity, which, so far forth, is to respect such freedom and refrain from interfering with it. The obligation being from the other view a right, each member of society has a right of free and uninterrupted self -development, which may for shortness be called his right of freedom. In its other regarding, or altruistic aspect, the obligation of reciprocity concerns the assistance due from each member within the social body to his fellows and to society, and due from society to each of its members. To refuse to render such assistance is a breach of the obligation of reciprocity, which, so far forth, is to render such assistance. Each member then has the right to such assistance, which may for shortness be called a right to co-operation. Thus two great classes of ethical rights are at once established. It may be noted in passing that the fullest performance of the altruistic obligation depends upon the fullest enjoyment of the egoistic right, and, conversely, that the fullest enjoyment of the egoistic right depends upon the fullest performance of the altruistic duty. It is only upon the condition that the individual and society are possessed of their utmost powers that they can render efficient aid to others, and it is only upon the condition that others assist them that they can themselves attain their highest develop- ment. It is thus in a very real sense true that the individual's highest self-development is a duty which he owes to others, and that their co-operation with him is their right which he must re- spect. In a manner, therefore, the principle of reciprocity returns upon itself. These considerations bring more clearly to view the esaential unity of the principle. Egoism and altruism, instead of being a conflicting duality of opposing forces, are harmonized into one law of distinguishable but inseparable aspects. Finally, be it observed, the organic relations which this principle involves would not be enlarged by showing the individual to be a member of another than the social organism. The same reasoning would
