Every branch of science must be carried to perfection by a master in it, formed by the hand of nature, and improved by application and experience. The great genius of Mr. de Colbert saw through the confusion and perplexity of the administration of the French finances; he invented resources for swelling the public treasure, which never would have been liable to so many inconveniencies as are complained of, had the administration been conducted with as much disinterestedness, as it was set on foot with ability. The genius of Mr. Law was original as to figures and paper credit. Sir Robert Walpole discovered new principles of taxation, he extended the plan of public credit, and reduced the application of it to a science. These were born statesmen, they were creators of new ideas, they found out new principles for the government of men, and led them by their interest to concur in the execution of their plans. Men of a speculative disposition may broach hints, although the force of theory, destitute of practice, and unassisted by experiment, be not sufficient to carry them the length of forming a plan. A great genius, with power and authority, has occasion for no more than a hint to strike out the system, and to carry it, with success, into execution. No problems of political oeconomy seem more obscure than those which influence the multiplication of the human species, and which determine the distribution and employment of them, so as best to advance the prosperity of each particular society. I have no where found these matters treated to my wish, nor have I ever been able to satisfy myself concerning them. There are many clouds which still cover the fruitful fields of this science; and until these be dissipated, the political eye cannot take in the whole landscape, nor judge of the deformities which appear in the many representations which our modern painters are daily giving of it. I may here, without an imputation of vanity, put myself so far upon a level with the great Montesquieu, as to adopt the saying of Correggio, _Io anche son pittore_; I am also a dawber; for I frankly acknowledge my own insufficiency to treat this subject with perspicuity: my frequent repetitions, and my often returning to it at different times, in order to clear up my ideas and those of my readers, shews plainly, that I am sensible of my own insufficiency. By setting it in different lights, and viewing it as it were from different stations, perhaps both my reader and I may come at last to see a little clearer.