A like conclusion is suggested when we look into the related controversy as to the respective provinces of common law and of legislation. Inheritance and succession, definition of interests in property and the conveyance thereof, matters of commercial law and the creation, incidents and transfer of obligations have proved a fruitful field for legislation. In these cases the social interest in the general security is the controlling element. But where the questions are not of interests of substance but of the weighing of human conduct and passing upon its moral aspects, legislation has accomplished little. No codification of the law of torts has done more than provide a few significantly broad generalizations. On the other hand, succession to property is everywhere a matter of statute law and commercial law is codified or codifying throughout the world. Moreover the common law insists upon its doctrine of _stare decisis_ chiefly in the two cases of property and commercial law. Where legislation is effective, there also mechanical application is effective and desirable. Where legislation is ineffective, the same difficulties that prevent its satisfactory operation require us to leave a wide margin of discretion in application, as in the standard of the reasonable man in our law of negligence and the standard of the upright and diligent head of a family applied by the Roman law, and especially by the modern Roman law, to so many questions of fault, where the question is really one of good faith. All attempts to cut down this margin have proved futile. May we not conclude that in the part of the law which has to do immediately with conduct complete justice is not to be attained by the mechanical application of fixed rules? Is it not clear that in this part of the administration of justice the trained intuition and disciplined judgment of the judge must be our assurance that causes will be decided on principles of reason and not according to the chance dictates of caprice, and that a due balance will be maintained between the general security and the individual human life?