The director wants to build a house. Now, there are many methods that can be resorted to. Each of them offers, from the point of view of the director, certain advantages and disadvantages with regard to the utilization of the future building, and results in a different duration of the building’s serviceableness; each of them requires other expenditures of building materials and labor and absorbs other periods of production. Which method should the director choose? He cannot reduce to a common denominator the items of various materials and various kinds of labor to be expended.

For more than a hundred years the substitution of socialist planning for private enterprise has been the main political issue. Thousands and thousands of books have been published for and against the communist plans. No other subject has been more eagerly discussed in private circles, in the press, in public gatherings, in the meetings of learned societies, in election campaigns, and in parliaments. Wars have been fought and rivers of blood have been shed for the cause of socialism. Yet in all these years the essential question has not been raised.

The socialist tracts deal with everything except the essential and unique problem of socialism, viz., economic calculation. It is only in the last years that socialist writers have no longer been able to avoid paying attention to this primordial matter. They have begun to suspect that the Marxian technique of smearing “bourgeois” economics is not a sufficient method for the realization of the socialist utopia. They have tried to substitute a theory of socialism for the scurrilous Hegelian metaphysics of the Marxian doctrine.

The entrepreneurs and capitalists do not have advance assurance about whether their plans are the most appropriate solution for the allocation of factors of production to the various branches of industry. It is only later experience that shows them after the event whether they were right or wrong in their enterprises and investments. The method they apply is the method of trial and error. Why, say some socialists, should not the socialist director resort to the same method?

The distinctive mark of socialism is the oneness and indivisibility of the will directing all production activities within the whole social [p. 706] system.

In order to appraise adequately the idea that the differential equations of mathematical economics could be utilized for socialist economic calculation, we must remember what these equations really mean.

ONE* OF THE UNHAPPY CASUALTIES of World War I, it seems, was the old-fashioned treatise on economic “principles.” Before World War I, the standard method, both of presenting and advancing economic thought, was to write a disquisition setting forth one’s vision of the corpus of economic science.