For a nation should only be given the laws and commandments that it can tolerate, as Solon said: "I have given them the best laws that they could endure," and the God of Israel said to the Jews: "I have given you precepts which are not good," that is to say, they have only the goodness which your wickedness will tolerate. "This is the sponge," says Montesquieu, "which wipes out all the difficulties that can be raised against the laws of Moses."
The legislator, then, ought to understand the temperament and genius of the people because he has to frame its laws. As the Germans say, he ought to be an expert on the psychology of races. Further, he ought to understand the temperament, peculiarities and character of the people, without sharing its temperament himself. For where the passions and inclinations are concerned, experience is not knowledge. On the contrary, experience prevents us from really knowing; and indeed one of the conditions of knowledge is absence of an experience which may be another word for bias.
The ideal legislator, or indeed any legislator worthy of the name, ought to understand the general tendencies of his people, but he ought to be able to view them from a position of detachment and to be able to control them, because it is his business partly to satisfy and partly to combat these tendencies.
He has partly to satisfy them, or at least, to consider them, because a law which outraged the national temperament would be like Roland's mare, which had every conceivable good quality with this one serious defect, that she was dead, and born dead. Suppose the Romans had been given an international law decreeing respect for conquered peoples, it would have been a dead letter, and by a sort of contagion it would have led to the neglect of other laws. Suppose the French were given a liberal law, a law prescribing respect for the individual rights of the man and the citizen. Liberty, the object of such a law, is for the French, as Baron Joannès has remarked: "The right of each man to do what he likes and to prevent other men from doing what they like." In France such a law would never obtain any but a very grudging allegiance, and it would certainly lead to the neglect of other laws.
The legislator ought therefore to understand the natural idiosyncrasies of his people in order to know how far he dare venture to oppose them.
Partly he must combat them, because law should be to a nation, or otherwise it is merely a police regulation, what the moral law is to an individual. Law should be a restraint imposed continuously in the hope of future improvements. It should be a curb on dangerous passions and injurious desires. It should aid the warfare of enlightened selfishness against the selfishness of which all are ashamed. That is what Montesquieu meant when he said that morals should correct climate, and laws should correct morals.
The law, therefore, to a certain extent should correct national tendencies, it should be loved a little because it is felt to be just, feared a little because it is severe, hated a little because it is to a certain degree out of sympathy with the prevalent temper of the day, and respected because it is felt to be necessary.
This is the law that the legislator has to frame, and therefore he ought to have expert knowledge of the genius of the people for whom he legislates. He must understand both those tendencies which will resist and those which will welcome him. He must know how far he can go unopposed and how much he can venture without forfeiting his authority.
This is the principal and essential qualification for the legislator.
The second, as we said before, is that he must be impartial. The very essence of the legislator is that he should have moderation, that virtue on which Cicero set so high a value, which is so rare, if we look to its real meaning, the perfect balance of soul and mind. "It seems to me," said Montesquieu: "and I have written this book solely to prove it, that the spirit of moderation is essential in a legislator, for political, as well as moral right, lies between two extremes."