That three centuries should have had to elapse before the solution could be found, is in perfect harmony with the other fact that it was reserved for these last generations to give us complete control over the forces of nature, and to render it possible for us to _make use_ of the knowledge we have acquired. For so long as human production was in the main dependent upon the capacity and strength of human muscles, aided by the muscles of a few domestic animals, more might certainly be produced than would be consumed by the luxury of a few after the bare subsistence of the masses had been provided for; but to afford to _all_ men an abundance without excessive labour needed the results of the substitution of the inexhaustible forces of nature for muscular energy. Until this substitution had become possible, it would have availed mankind little to have attained to a knowledge of the ultimate ground of the hindrance to the full utilisation of the then existing powers of production. For in order that the exploitage of man by man might be put an end to, it was necessary that the amount of producible wealth should not merely exceed the consumption of the few wealthy persons, but should be sufficient to satisfy the higher human needs of all. Economic equity, if it is not to bring about a stagnation in civilisation, assumes that the man who has to depend upon the earnings of his own labour is in a position to enjoy a considerable amount of wealth at the cost of moderate effort. This has become possible only during the last few generations; and herein is to be sought the reason why the great economists of the seventeenth and eighteenth centuries were not able to rise to an unprejudiced critical examination of the true nature and the necessary consequences of the exploiting system of industry. _They_ were compelled to regard exploitage as a cruel but eternally unavoidable condition of the progress of civilisation; for when they lived it was and it always had been a necessity of civilisation, and they could not justly be expected to anticipate such a fundamental revolution in the conditions of human existence as must necessarily precede the passage from exploitage to economic equity.