But as the soul advances to a fuller exercise of its powers, the animal appetites, and the passions immediately arising from them, are not sufficient to find it employment; the wants of nature are soon supplied, the fear of their return is easily precluded, and something more is necessary to relieve the long intervals of inactivity, and to give those faculties, which cannot lie wholly quiescent, some particular direction. For this reason, new desires and artificial passions are by degrees produced; and, from having wishes only in consequence of our wants, we begin to feel wants in consequence of our wishes; we persuade ourselves to set a value upon things which are of no use, but because we have agreed to value them; things which can neither satisfy hunger, nor mitigate pain, nor secure us from any real calamity, and which, therefore, we find of no esteem among those nations whose artless and barbarous manners keep them always anxious for the necessaries of life. This is the original of avarice, vanity, ambition, and generally of all those desires which arise from the comparison of our condition with that of others. He that thinks himself poor because his neighbour is richer; he that, like Cæsar, would rather be the first man of a village, than the second in the capital of the world, has apparently kindled in himself desires which he never received from nature, and acts upon principles established only by the authority of custom. Of these adscititious passions, some, as avarice and envy, are universally condemned; some, as friendship and curiosity, generally praised; but there are others about which the suffrages of the wise are divided, and of which it is doubted, whether they tend most to promote the happiness, or increase the miseries of mankind.