The sanction of the Law is stricter than that of Custom, just as the Law itself is stricter than is Custom. The Law concerns itself with concrete cases in which consideration for one's fellow men must be practised, duties to him fulfilled, and his claims respected. These cases are defined by Law as clearly as possible, whereas Custom confines itself to generalities and determines the whole attitude of the individual to his neighbour. Custom embraces the outer and inner life of man and supervises his opinions, which are the parents of his deeds, and also his deeds themselves; Law is only concerned with actions, and refrains from penetrating to the intimacy of thoughts, unless the latter alter the essential character of the action, as premeditation in an act of revenge and temporary or permanent irresponsibility alter the judgment of offences and crimes. Law is a miserly extract of custom, a meagre selection from its variety, a concentration and embodiment of its surging vagueness. It may be compared with crystals, which in their geometrically accurate forms are crystallized clearly and definitely out of a liquid, the mother liquor; or with the heavenly bodies which agglomerate out of surging primal nebulæ. Custom is the primitive thing, Law is derived from it. It appeals to its descent from Custom, and founds, at any rate tacitly, its claim to respect on these grounds. A law which ran counter to Custom, which was confessedly in opposition to Custom, could never be maintained or prevail, though it bristled with the menace of the most dreadful punishments.
The relationship of mother to child between Custom and Law may be obscure to the majority; it is clear to the analytical mind. Recognition of the essential unity of both phenomena explains an assumption which was widespread among the best intellects from the Middle Ages until well into the eighteenth century, but which has now been abandoned as erroneous by more positive, though indeed narrower, legal minds. This assumption is that there is a natural Law antecedent to historical Law, which exists and acts beside and above the latter, and which forms the basis and the measure of every positive law, of every concrete legal judgment. It is comprehensible that the nineteenth century swept away the idea of natural Law and freely made fun of it. To a sternly disciplined legal mind it must indeed seem grotesque if a judge, in order to arrive at a verdict in some concrete dispute, cites the rights to which man is born instead of a certain text of the law, or even, following Schiller's advice, reaches up to the stars and brings down thence the eternal Law. Even this procedure is not so farcical as it seems to stupid article-mongers and hair-splitting paragraphists, for the procedure of equity of the English judges, who are not prone to clowning, is at bottom nothing but this reaching up to the stars and this judging by the rights to which man is born. The feud between natural Law and historical Law was really a quarrel about a word. Jean Jacques Rousseau, his contemporaries and disciples, simply made a mistake in their choice of an expression. They were guilty of an inaccuracy when they spoke of natural Law. They should have said: "the innate claim of man that his person should be respected," or, "natural consideration for one's fellow man," or, most shortly and simply, "Morality." To the latter legal lights would have raised none of the objections with which they victoriously opposed natural Law.