So long as the exploitage of man by man was considered a necessary and eternal institution, there existed no motive to prompt men to subject it to a closer critical investigation; and in the absence of such an investigation its influence upon the nature and extent of demand could not be discovered. The old economists were therefore _compelled_ to believe it chimerical to think of demand as falling short of production; for they said, quite correctly, that man produces only to consume. Here, with them, the question of demand was done with, and every possibility of the discovery of the true connection cut off. Their successors, on the other hand, who have all been witnesses of the undreamt-of increase of the productiveness of labour, have hitherto been prevented, by their otherwise well-justified respect for the authority of the founders of our science, from adequately estimating the economic importance of this revolution in the conditions of labour. The classical system of economics is based upon a conception of the world which takes in all the affairs of life, is self-consistent, and is supported by all the past teachings of the great forms of civilisation; and if we would estimate the enormous force with which this doctrine holds us bound, we must remember that even those who were the first to recognise its incongruity with existing facts were unable to free themselves from its power. They persisted in believing in it, though they perceived its incompatibility with the facts, and knew therefore that it was false. This glance at the historical evolution of economic doctrine opens the way to the rectification of all the errors of which the different schools of political economy have--even in their quest after truth--been guilty. It is seen that the great inquirers and thinkers of past centuries, in their vast work of investigation and analysis of economic facts, approached so very near to the full and complete cognisance of the true connection of all phenomena, that it needed but a little more labour in order to construct a thoroughly harmonious definitive economic theory based upon the solution, at last discovered, of the long vexed problem.