Finally, the theory of rent seems to give colour to certain theories which predict an extremely dark future for the race, corroborating the gloomy forebodings of Malthus. As society grows and advances it will be forced to employ lands that are less fertile and means of production that are more onerous. It seems as if the curse uttered in Genesis has been scientifically verified. “Thorns also and thistles shall it bring forth to thee; … in the sweat of thy face shalt thou eat bread.” True, he did not carry his pessimism so far as to say that as the result of this fatal exhaustion of this most precious instrument of production the progress of mankind would for ever be arrested by the ravages of famine. Other beneficent forces, the progress of agricultural science and a larger employment of capital, would surmount the difficulty. “Although the lands that are actually being cultivated may be inferior to those which were in cultivation some years ago, and consequently production is becoming more difficult, can anyone doubt that the quantity of products does not greatly exceed that formerly produced?” Ricardo’s theory does not involve a denial of progress. But it shows how the struggle is becoming more and more difficult, and how scarcity and want, if not actual famine, must lie in the path along which we are advancing. Suppose Great Britain were now to attempt to feed her 45 million inhabitants from her own soil, would there be much doubt as to the correctness of Ricardo’s prophecy? It is an easy matter to reproach Ricardo[344] with his failure to foresee the remarkable development in the methods of transport and cheap importation which resulted in the arrest, if not the reversal, of the upward movement of the rent curve. The complaints of landlords both in England and Europe seem to belie the Ricardian theory.[345] But who can tell whether the peril is finally removed or not? The inevitable day will arrive when new countries will consume the corn which to-day they export. This may not come about in the history of England and Europe for some centuries yet, but when it does happen, rent, instead of being stationary and retrogressive, as it has been so long, will again resume its upward trend. It is true that we may reckon upon the aid of agricultural science even if foreign importation should fail us. Ricardo was ever mindful of the great possibilities of human industry. Other economists, notably Carey and Fontenay, one of Bastiat’s disciples, have propounded a theory which is the exact antithesis of the Ricardian, namely, that human industry in its utilisation of natural forces always begins with the feeblest as being more easily tamed, the more powerful and recalcitrant forces only coming in for attention later on. The earth is no exception to the rule, and agricultural industry might well become not less but more productive. This thesis, which implies a negation of the law of diminishing returns, is based upon a very debatable analogy.