Ricardo set out to demonstrate the antagonism,[340] and with what a vigorous pen does he not picture it! The study of this question of rent made of him a Free Trader stauncher than Adam Smith, more firmly convinced than the Physiocrats. Free Trade was for them founded upon the conception of a general harmony of interests, while Ricardo built his faith upon one clearly demonstrated fact—the high price of corn and its concomitant, high rents. Free Trade seemed to be the means of checking this disastrous movement. The free importation of corn implied the cultivation of distant lands as rich as or even richer than any in Britain. All this meant avoiding the cultivation of inferior lands and reducing the high price of corn. He was also desirous of proving to the proprietors that the practice of free exchange, even though it might involve some loss of revenue to them, was really to their interest. Their opposition, he thought, was very short-sighted. “They fail to see,” he writes, “that commerce everywhere tends to increase production, and that as a result of this increased production general well-being is also improved, although there may be partial loss as the result of it. To be consistent with themselves they ought to try to arrest all improvement in agriculture and manufacture and all invention of machinery.”[341] The theory of rent, in the second place, endangered the reputation of landowners by showing that their income is not the product of labour, and is consequently anti-social. No wonder that it has been so severely criticised by conservative economists. Ricardo himself, however, seemed quite unconscious of the nature of the blow thus aimed at the institution of private property. His indifference, which appears to us so surprising, is partly explained by the fact that the theory absolved the proprietor from all responsibility in the matter. Unlike profits and wages, rent does not figure in cost of production because it makes no contribution to the price of corn, but is itself wholly determined by that price.[342] The landed proprietor thus appears as the most innocent of the co-partners, playing a purely passive _rôle_. He does not produce rent, but simply accepts it. That may be; but the fact that the proprietor plays no part in the production of rent, whilst exonerating him from complicity in its invidious consequences, spells ruin to his title of proprietor—that is, if we consider labour to be the only title to proprietorship. It was just this aspect of the question that drew the attention of Ricardo’s contemporary James Mill. Mill advocated the confiscation of rent or its socialisation by means of taxation.[343] He thus became a pioneer in the movement for land nationalisation, a cause that has since been championed by such writers as Colins, Gossen, Henry George, and Walras.