It is the more singular that Rousseau should have thus deliberately put aside all but the most arbitrary and empirical historical lessons, and it shows the extraordinary force with which men may be mastered by abstract prepossessions, even when they have a partial knowledge of the antidote; because Rousseau in several places not only admits, but insists upon, the necessity of making institutions relative to the state of the community, in respect of size, soil, manners, occupation, morality, character. "It is in view of such relations as these that we must assign to each people a particular system, which shall be the best, not perhaps in itself, but for the state for which it is destined."[185] In another place he calls attention to manners, customs, above all to opinion, as the part of a social system on which the success of all the rest depends; particular rules being only the arching of the vault, of which manners, though so much tardier in rising, form a key-stone that can never be disturbed.[186] This was excellent so far as it went, but it was one of the many great truths, which men may hold in their minds without appreciating their full value. He did not see that these manners, customs, opinions, have old roots which must be sought in a historic past; that they are connected with the constitution of human nature, and that then in turn they prepare modifications of that constitution. His narrow, symmetrical, impatient humour unfitted him to deal with the complex tangle of the history of social growths. It was essential to his mental comfort that he should be able to see a picture of perfect order and logical system at both ends of his speculation. Hence, he invented, to begin with, his ideal state of nature, and an ideal mode of passing from that to the social state. He swept away in his imagination the whole series of actual incidents between present and past; and he constructed a system which might be imposed upon all societies indifferently by a legislator summoned for that purpose, to wipe out existing uses, laws, and institutions, and make afresh a clear and undisturbed beginning of national life. The force of habit was slowly and insensibly to be substituted for that of the legislator's authority, but the existence of such habits previously as forces to be dealt with, and the existence of certain limits of pliancy in the conditions of human nature and social possibility, are facts of which the author of the Social Contract takes not the least account.