 As to pleasures of the same kind, ’tis manifest their values are in a joint proportion of their intenseness and duration. In estimating the duration, we not only regard the constancy of the object, or its remaining in our power, and the duration of the sensations it affords, but the constancy of our fancy or relish: for when this changes it puts an end to the enjoyment. In comparing pleasures of different kinds, the value is as the duration and dignity of the kind jointly. We have an immediate sense of a dignity, a perfection, or beatifick quality in some kinds, which no intenseness of the lower kinds can equal, were they also as lasting as we could wish. No intenseness or duration of any external sensation gives it a dignity or worth equal to that of the improvement of the soul by knowledge, or the ingenious arts; and much less is it equal to that of virtuous affections and actions. (System, 117)