A treatise has no doubt unquestionable superiority, but on one condition—namely, that it is read and carefully pondered and thought over. It is addressed to a select class of readers. Its mission is to fix first of all, and afterwards enlarge, the circle of our acquired knowledge.

A refutation of vulgar errors and prejudices cannot occupy this high position. It aspires merely to clear the road before the march of truth, to prepare men's minds for its reception, to rectify public opinion, and disarm dangerous ignorance.

It is, above all, in the department of Social Economy that this hand-to-hand struggle, that these constantly-recurring battles with popular errors, are of true practical utility.

The sciences may be divided into two classes.

One of these classes may be known only to savans. It includes those sciences the application of which constitutes the business of special professions. The vulgar reap the fruit, in spite of their ignorance. A man may find use for a watch, though ignorant of mechanics and astronomy, and he may be carried along by a locomotive or a steamer, trusting to the skill of the engineer and the pilot. We walk according to the laws of equilibrium, although unacquainted with these laws, just as M. Jourdain had talked prose all his life without knowing it.

But there are sciences which exercise on the public mind an influence which is only in proportion to public enlightenment, and derive all their efficacy, not from knowledge accumulated in some gifted minds, but from knowledge diffused over the general masses. Among these we include morals, medicine, social economy, and, in countries where men are their own masters, Politics. It is to such sciences that the saying of Bentham specially applies, "To disseminate them is better than to advance them." What signifies it, that some great man, or even that God himself, should have promulgated the laws of morality, as long as men, imbued with false notions, mistake virtues for vices, and vices for virtues? What matters it that Smith, Say, and, according to M. de Saint-Chamans, economists of all schools, have proclaimed, in reference to commercial transactions, the superiority of liberty over constraint, if the men who make our laws, and for whom our laws are made, think differently?

Those sciences, which have been correctly named social, have also this peculiarity, that being of universal and daily application, no one will confess himself ignorant of them. When the business is to resolve a question in chemistry or geometry, no one pretends to have acquired these sciences by intuition, no one is ashamed to consult M. Thenard, or makes any difficulty about referring to the works of Legendre or Bezout. But in the social sciences, authority is scarcely acknowledged. As each man daily takes charge of his morals, whether good or bad, of his health, of his purse, of his politics, whether sound or absurd, so each man believes himself qualified to discuss, comment, and pronounce judgment on social questions. Are you ill? There is no old woman who will not at once tell you the cause of your ailment, and the remedy for it. "Humours," she will say; "you must take physic." But what are humours? and is there any such disease? About this she gives herself no concern. I cannot help thinking of this old woman when I hear social maladies explained by these hackneyed phrases:—"The superabundance of products," "the tyranny of capital," "an industrial plethora," and other such commonplaces, of which we cannot even say, Verba et voces, protereaque nihil, for they are so many pestilent errors.

From what I have said, two things result—1st, That the social sciences must abound more in sophisms than others, because in them each man takes counsel of his own judgment and instincts; 2d, That it is in these sciences that sophisms are especially mischievous, because they mislead public opinion, and in a matter, too, with reference to which public opinion is force, is law.

In these sciences, then, we have need of two sorts of books, those which explain them, and those which further and advance them—those which establish truth, and those which combat error.

It seems to me that the inherent fault of this little work, repetition, is exactly what will make it useful.