There is no part of philosophy of more importance, than a just knowledge of human nature, and its various powers and dispositions. Our late inquirys have been very much employed about our understanding, and the several methods of obtaining truth. We generally acknowledge, that the Importance of any truth is nothing else than its moment, or efficacy to make men happy, or to give them the greatest and most lasting pleasure; and wisdom denotes only a capacity of pursuing this end by the best means. It must surely then be of the greatest importance, to have distinct conceptions of this end itself, as well as of the means necessary to obtain it; that we may find out which are the greatest and most lasting pleasures, and not employ our reason, after all our laborious Improvements of it, in trifling pursuits. It is to be feared indeed, that most of our studies, without this inquiry will be of very little use to us; for they seem to have scarce any other tendency than to lead us into speculative knowledge itself. Nor are we distinctly told how it is that knowledge, or truth, is pleasant to us. This consideration put the author of the following papers upon inquiring into the various pleasures which human nature is capable of receiving. We shall generally find in our modern philosophic writings, nothing farther on this head, than some bare division of them into sensible, and rational, and some trite commonplace arguments to prove the latter more valuable than the former. Our sensible pleasures are slightly passed over, and explained only by some instances in tastes, smells, sounds, or such like, which men of any tolerable reflection generally look upon as very trifling satisfactions. Our rational pleasures have had much the same kind of treatment. We are seldom taught any other notion of rational pleasure than that which we have upon reflecting on our possession, or claim to those objects, which may be occasions of pleasure. Such objects we call advantageous; but advantage, or interest, cannot be distinctly concerned, till we know what those pleasures are which advantageous objects are apt to excite; and what senses or powers of perception we have with respect to such objects. We may perhaps find such an inquiry of more importance in morals, to prove what we call the reality of virtue, or that it is the surest happiness of the agent, than one would at first imagine. In reflecting upon our external senses, we plainly see, that our perceptions of pleasure, or pain, do not depend directly on our will. Objects do not please us, according as we incline they should. The presence of some objects necessarily pleases us, and the presence of others as necessarily displeases us. Nor can we by our will, any otherwise procure pleasure, or avoid pain, than by procuring the former kind of objects, and avoiding the latter. By the very frame of our nature the one is made the occasion of delight, and the other of dissatisfaction. The same observation will hold in all our other pleasures and pains.--Preface. (PsycINFO Database Record (c) 2008 APA, all rights reserved).