The first important means to secure this which the author would suggest is simply an extension of the common-law principle of non-discrimination. A man in conducting certain sorts of business is permitted to do as he chooses. He may sell to one person and refuse to sell to another; he may give to one and withhold from another. But if he enters business as the keeper of an inn or as a common carrier of passengers or freight, he can no longer exercise partiality. He has _elected to become a necessary servant of the public_, and as such he is bound to serve impartially all who apply. In the same way a manufacturer while he engages in business under the usual laws of competition, may sell to whom he pleases and exercise such preference as he chooses. But when he combines with all other manufacturers of the same sort in a combination to restrict competition, he and his allies voluntarily change their relation to the public. Is it not true that they do actually _elect to become necessary servants of the public_--far more necessary, indeed, than the inn-keeper or the stage-coach driver,--and ought they not therefore to be placed under similar legal restrictions? In every case where combination or consolidation restricts competition in an industry, one effect produced is an increase in the power over the public which the industry possesses. But this increased power over the public, thus voluntarily assumed, must inevitably carry with it increased responsibility to the public. It is the duty of the government to see that this responsibility is legally enforced. This first principle, then, should be embodied in a law providing, in substance, that every person or firm entering into a contract to restrict competition should, so long as that contract was in force, be debarred from showing any preference in his or its purchases and sales, by giving more or less favorable prices to any person or firm than those quoted to any other person or firm. To enforce this requirement and prevent its evasion it is necessary to provide also that prices shall be public and that they shall not be altered without due notice. The requirement of publicity might be best effected by providing that the contract restricting competition should contain a schedule of prices, which would usually be the case in any event. While this may seem like quite an assumption of authority on the part of the State, it is exactly what trusts and trade associations are striving to effect, though with the important qualification that when occasion, in the shape of an obnoxious competitor, requires, they wish to be at liberty to put prices up or down at short notice and exercise their preferences as they choose.