Smith, being now desirous of showing that international trade necessarily benefits both countries, bases his argument upon the fact that the merchants in both countries must make a profit—_i.e._ get an additional exchange value, which must be added to the others. To this Ricardo justly replied that the profits of a merchant do not necessarily increase the sum of utilities possessed by any country. Here again, in striking contrast with the attitude of the Physiocrats, Smith, despite himself, has championed his own adversaries. As yet he is not sufficiently rid of Mercantilist prejudice not to be concerned with the welfare of the producer, and in his great work we find excellent argument and debatable points of view placed side by side. It does not appear that he himself realised this incompatibility. An irresistible tide was sweeping everybody before it in the direction of a more liberal policy. It proved too powerful for his contemporaries, who were not concerned to give a careful consideration to every part of his thesis. Enough that they found in him an ardent champion of an attractive cause. We have already noticed more than once the hesitation which Smith displays when he comes to apply his principle, and we must again refer to it in this connection. Theoretically a champion of absolutely free exchange, he mitigates his belief in practice, and mentions an exception to his policy which seemed to him a mere matter of common sense. “To expect, indeed, that the freedom of trade should ever be entirely restored in Great Britain, is as absurd as to expect that an Oceana or Utopia should ever be established in it. Not only the prejudices of the public, but what is more unconquerable, the private interests of many individuals, irresistibly oppose it.”[239] Facts have belied this prophecy, like many others. England of the nineteenth century succeeded in realising this Utopia of free exchange—almost to perfection. Without any illusion as to the future, his condemnation of the past was not altogether unqualified. He justified some of the acts that were inspired by Mercantilism. “The act of navigation[240] is not favourable to foreign commerce,” said he; “as defence, however, is of much more importance than opulence, the act of navigation is, perhaps, the wisest of all the commercial regulations of England.”[241] In another instance he justifies an import duty where a tax is levied upon goods similar to those imported. Here an import duty merely restores that normal state of competition which was upset by the imposition of the Excise. Retaliation as a means of securing the abolition of foreign duties is not altogether under his ban.[242] And he finally admits that liberty is best introduced gradually into those countries in which industry has long enjoyed Protection or where a great number of men are employed.[243]