T 2.1.6.9

It may not be amiss to observe on this occasion, that the influence of general rules and maxims on the passions very much contributes to facilitate the effects of all the principles, which we shall explain in the progress of this treatise. For 'tis evident, that if a person full-grown, and of the same nature with ourselves, were on a sudden transported into our world, he wou'd be very much embarrass'd with every object, and wou'd not readily find what degree of love or hatred, pride or humility, or any other passion he ought to attribute |to it. The passions are often vary'd by very inconsiderable principles; and these do not always play with a perfect regularity, especially on the first trial. But as custom and practice have brought to light all these principles, and have settled the just value of every thing; this must certainly contribute to the easy production of the passions, and guide us, by means of general establish'd maxims, in the proportions we ought to observe in preferring one object to another. This remark may, perhaps, serve to obviate difficulties, that may arise concerning some causes, which I shall hereafter ascribe to particular passions, and which may be esteem'd too refin'd to operate so universally and certainly, as they are found to do.