To prove that the balance of trade, in spite of a prevailing impression to the contrary, not only might be, but had been, on the side of England, was the chief purpose of _Mercator_. The Whig _Flying Post_ chaffed _Mercator_ for trying to reconcile impossibilities, but _Mercator_ held stoutly on with an elaborate apparatus of comparative tables of exports and imports, and ingenious schemes for the development of various branches of the trade with France. Defoe was too fond of carrying the war into the enemy's country, to attack prohibitions or the received doctrine as to the balance of trade in principle; he fought the enemy spiritedly on their own ground. "Take a medium of three years for above forty years past, and calculate the exports and imports to and from France, and it shall appear the balance of trade was always on the English side, to the loss and disadvantage of the French." It followed, upon the received commercial doctrines, that the French King was making a great concession in consenting to take off high duties upon English goods. This was precisely what Defoe was labouring to prove. "The French King in taking off the said high duties ruins all his own manufactures." The common belief was that the terms of peace would ruin English manufacturing industry; full in the teeth of this, Defoe, as was his daring custom, flung the paradox of the extreme opposite. On this occasion he acted purely as a party writer. That he was never a free-trader, at least in principle, will appear from the following extract from his _Plan of the English Commerce_, published in 1728:--
"Seeing trade then is the fund of wealth and power, we cannot wonder that we see the wisest Princes and States anxious and concerned for the increase of the commerce and trade of their subjects, and of the growth of the country; anxious to propagate the sale of such goods as are the manufacture of their own subjects, and that employs their own people; especially of such as keep the money of their dominions at home; and on the contrary, for prohibiting the importation from abroad of such things as are the product of other countries, and of the labour of other people, or which carry money back in return, and not merchandise in exchange."