But there are sciences which exercise upon the public an influence proportionate with the light of the public itself, not from knowledge accumulated in a few exceptional heads, but from that which is diffused through the general understanding. Such are morals, hygiene, social economy, and in countries which men belong to themselves, politics. It is of these sciences, above all, that Bentham might have said: "That which spreads them is worth more than that which advances them." Of what consequence is it that a great man, a God even, should have promulgated moral laws, so long as men, imbued with false notions, take virtues for vices, and vices for virtues? Of what value is it that Smith, Say, and, according to Chamans, economists of all schools, have proclaimed the superiority of liberty to restraint in commercial transactions, if those who make the laws and those for whom the laws are made, are convinced to the contrary. These sciences, which are well named social, have this peculiarity: that for the very reason that they are of a general application, no one confesses himself ignorant of them. Do we wish to decide a question in chemistry or geometry? No one pretends to have the knowledge instinctively; we are not ashamed to consult Draper; we make no difficulty about referring to Euclid. But in social science authority is but little recognized. As such a one has to do daily with morals, good or bad, with hygiene, with economy, with politics reasonable or absurd, each one considers himself skilled to comment, discuss, decide, and dogmatize in these matters. Are you ill? There is no good nurse who does not tell you, at the first moment, the cause and cure of your malady. "They are humors," affirms she; "you must be purged." But what are humors? and are these humors? She does not trouble herself about that. I involuntarily think of this good nurse when I hear all social evils explained by these common phrases: "It is the superabundance of products, the tyranny of capital, industrial plethora," and other idle stories of which we cannot even say: _verba et voces prætereaque nihil_: for they are also fatal mistakes. From what precedes, two things result-- 1st. That the social sciences must abound in sophistry much more than the other sciences, because in them each one consults his own judgment or instinct alone. 2d. That in these sciences sophistry is especially injurious, because it misleads public opinion where opinion is a power--that is, law. Two sorts of books, then, are required by these sciences; those which expound them, and those which propagate them; those which show the truth, and those which combat error. It appears to us that the inherent defect in the form of this little Essay--_repetition_--is that which constitutes its principal value.