17. But take note here. We have just seen that the sum of the perceptive faculty is expressed in these words of Aristotle's, "to take pleasure rightly" or straightly--[Greek: chairein orthos]. Now, it is not possible to do the direct opposite of that,--to take pleasure iniquitously or obliquely--[Greek: chairein adikos] or [Greek: skolios],--more than you do in enjoying a thing because your neighbor cannot get it. You may enjoy a thing legitimately because it is rare, and cannot be seen often (as you do a fine aurora, or a sunset, or an unusually lovely flower); that is Nature's way of stimulating your attention. But if you enjoy it because your neighbor cannot have it,--and, remember, all value attached to pearls more than glass beads, is merely and purely for that cause,--then you rejoice through the worst of idolatries, covetousness; and neither arithmetic, nor writing, nor any other so-called essential of education, is now so vitally necessary to the population of Europe, as such acquaintance with the principles of intrinsic value, as may result in the iconoclasm of jewelry; and in the clear understanding that we are not, in that instinct, civilized, but yet remain wholly savage, so far as we care for display of this selfish kind. You think, perhaps, I am quitting my subject, and proceeding, as it is too often with appearance of justice alleged against me, into irrelevant matter. Pardon me; the end, not only of these Lectures, but of my whole Professorship, would be accomplished,--and far more than that,--if only the English nation could be made to understand that the beauty which is indeed to be a joy forever, must be a joy for all; and that though the idolatry may not have been wholly divine which sculptured gods, the idolatry is wholly diabolic, which, for vulgar display, sculptures diamonds. 18. To go back to the point under discussion. A pearl, or a glass bead, may owe its pleasantness in some degree to its luster as well as to its roundness. But a mere and simple ball of unpolished stone is enough for sculpturesque value. You may have noticed that the quatrefoil used in the Ducal Palace of Venice owes its complete loveliness in distant effect to the finishing of its cusps. The extremity of the cusp is a mere ball of Istrian marble; and consider how subtle the faculty of sight must be, since it recognizes at any distance, and is gratified by, the mystery of the termination of cusp obtained by the gradated light on the ball.