Both of these ideas, natural rights and an ideal form of the actual law of the time and place as the jural order of nature, were handed down to and put to new uses in the nineteenth century. In the growing law of the seventeenth and eighteenth centuries they were but guides to lead growth into definite channels and insure continuity and permanence in the development of rules and doctrines. Whether natural rights were conceived as qualities of the natural man or as deductions from a compact which expressed the nature of man, the point was, not that the jurist should keep his hands off lest by devising some new precept or in reshaping some old doctrine he infringe a fundamental right, but that he should use his hand freely and skilfully to shape rules and doctrines and institutions that they might be instruments of achieving the ideal of human existence in a "state of nature." For the state of nature, let us remember, was a state which expressed the ideal of man as a rational creature. If a reaction from the formal over-refinement of the eighteenth century came to identify this with a primitive simplicity, in juristic hands it was the simplicity of a rational ideal in place of the cumbrous complexity of legal systems which had become fixed in their ideas in the stage of the strict law. Thus Pothier, discussing the Roman categories of contract and rejecting them for the "natural" principle that man, as a moral creature, should keep his engagements, declares that the complex and arbitrary system of Roman law, made up of successive additions at different times to a narrow primitive stock of legally enforceable promises, is not adhered to because it is "remote from simplicity." Again the ideal form of the actual law, which gave content to natural law, was not an ideal form of historically found principles, constraining development for all time within historically fixed bounds, as in the nineteenth century, but an ideal form of the _ratio legis_--of the reason behind the rule or doctrine or institution whereby it expressed the nature of the rational human being guided only by reason and conscience in his relations with similar beings similarly guided. Attempts to fix the immutable part of law, to lay out legal charts for all time, belong to the transition to the maturity of law. The eighteenth-century projects for codification and the era of codification on the Continent, in which the results of two centuries of growth were put in systematic form to serve as the basis of a juristic new start, in form rested upon the theory of natural law. By a sheer effort of reason the jurist could work out a complete system of deductions from the nature of man and formulate them in a perfect code. Go to, let him do so! This was not the mode of thought of a period of growth but rather of one when growth had been achieved and the philosophical theory of a law of nature was called upon for a new kind of service.