A crisis is the result of overproduction. This does not imply that in every case overproduction will bring about a crisis. If one who is producing for his own consumption happens to produce more than he can consume, the result will be that during a certain period he will proceed to produce less, and the equilibrium will be reëstablished. But when one manufactures not for himself but for the market the situation is entirely different. Each manufacturer of commodities produces separately, that is to say without any understanding with his fellow-manufacturers, articles of which he himself has no need, but which he attempts to exchange for money in order to obtain what he does need. If he does not succeed in selling his commodities he is left without money to buy the commodities that are necessary to him. Overproduction can thus have very harmful results for those who hold commodities. Now how does it happen that the capitalistic mode of production causes periodically a production greater than the possible consumption? (It goes without saying that this phrase is not to be taken to mean that the consumers are physically incapable of using the product, but merely that there are not enough buyers.) As has been shown above, capitalistic production is carried on for the sake of the added value, that is to say, the value of the unpaid labor. In other words, the working class produces more than it consumes. In feudal society the surplus was entirely consumed by the class which appropriated it; at present, on the contrary, the owning class use part of the surplus to form new capital. For this comes a continually increasing accumulation of capital, and consequently a greater and greater quantity of products which in the end find no buyer. For the extension of production increases the number of workmen necessary, and consequently increases the demand also, but these workmen produce in their turn more than they consume. The overproduction is not, then, neutralized by a greater consumption. On the contrary it furnishes the material for an overproduction still greater. Hence capitalism causes crises periodically as the result of an overproduction caused by too small a consumption on the part of the working class.