All people of shallow thought are apt to decry even those of solid understanding, as abstruse thinkers, and metaphysicians, and refiners; and never will allow anything to be just which is beyond their own weak conceptions. There are some cases, I own, where an extraordinary refinement affords a strong presumption of falsehood, and where no reasoning is to be trusted but what is natural and easy. When a man deliberates concerning his conduct in any particular affair, and forms schemes in politics, trade, economy, or any business in life, he never ought to draw his arguments too fine, or connect too long a chain of consequences together. Something is sure to happen that will disconcert his reasoning, and produce an event different from what he expected. But when we reason upon general subjects, one may justly affirm that our speculations can scarce ever be too fine, provided they be just; and that the difference between a common man and a man of genius is chiefly seen in the shallowness or depth of the principles upon which they proceed. General reasonings seem intricate, merely because they are general; nor is it easy for the bulk of mankind to distinguish, in a great number of particulars, that common circumstance in which they all agree, or to extract it, pure and unmixed, from the other superfluous circumstances. Every judgment or conclusion, with them, is particular. They cannot enlarge their view to those universal propositions which comprehend under them an infinite number of individuals, and include a whole science in a single theorem. Their eye is confounded with such an extensive prospect; and the conclusions derived from it, even though clearly expressed, seem intricate and obscure. But however intricate they may seem, it is certain that general principles, if just and sound, must always prevail in the general course of things, though they may fail in particular cases; and it is the chief business of philosophers to regard the general course of things. I may add that it is also the chief business of politicians; especially in the domestic government of the state, where the public good, which is, or ought to be, their object, depends on the concurrence of a multitude of cases; not, as in foreign politics, on accidents and chances, and the caprices of a few persons. This therefore makes the difference between particular deliberations and general reasonings, and renders subtlety and refinement much more suitable to the latter than to the former. I thought this introduction necessary before the following discourses on commerce, money, interest, balance of trade, etc., where, perhaps, there will occur some principles which are uncommon, and which may seem too refined and subtle for such vulgar subjects. If false, let them be rejected; but no one ought to entertain a prejudice against them merely because they are out of the common road.