his goods to a willing purchaser, therefore he must devote himself to the production of things which others need, things, therefore, of social value. He will, by preference, make that for which he can obtain the highest price, and this will be that for which, at the particular time and place and in relation to his particular capacities, there is the greatest need. He will, again, find the employer who will pay him best, and that will be the employer to whom he can do the best service. Self-interest, if enlightened and unfettered, will, in short, lead him to conduct coincident with public interest. There is, in this sense, a natural harmony between the individual and society. True, this harmony might require a certain amount of education and enlightenment to make it effective. What it did not require was governmental "interference," which would always hamper the causes making for its smooth and effectual operation. Government must keep the ring, and leave it for individuals to play out the game. The theory of the natural rights of the individual is thus supplemented by a theory of the mutual harmony of individual and social needs, and, so completed, forms a conception of human society which is _prima facie_ workable, which, in fact, contains important elements of truth, and which was responsive to the needs of a great class, and to many of the requirements of society as a whole, during a considerable period. On both sides, however, the theory exhibits, under criticism, fundamental weaknesses which have both a historical and a speculative significance. Let us first consider the conception of natural rights. What were these rights, and on what did they rest? On the first point men sought to be explicit. By way of illustration we cannot do better than quote the leading clauses of the Declaration of 1789.[5] _Article I._--Men are born and remain free and equal in rights. Social distinctions can only be founded on common utility. _Article II._--The end of every political association is the conservation of the natural and imprescriptible rights of man.[6] These rights are liberty, property, security (_la surete_), and resistance to oppression. _Article III._--The principle of all sovereignty resides essentially in the nation.... _Article IV._--Liberty consists in the power to do anything that does not injure others; thus, the exercise of the natural rights of every man has only such limits as assure to other members of society the enjoyment of the same rights. These limits can only be determined by law. _Article VI._--The law is the expression of the general will. All citizens have a right to take part (_concourir_), personally or by their representatives, in its formation. The remainder of this article insists on the impartiality of law and the equal admission of all citizens to office. The Declaration of 1793 is more emphatic about equality, and more rhetorical. Article III reads, "All men are equal by nature and before the law."