T 2.2.11.6

This may also serve in another view to illustrate what I have insisted on concerning the origin of pride and humility, love and hatred. I have observ'd, that tho' self be the object of the first set of passions, and some other person of the second, yet these objects cannot alone be the causes of the passions; as having each of them a relation to two contrary affections, which must from the very first moment destroy each other. Here then is the situation of the mind, as I have already describ'd it. It has certain organs naturally fitted to produce a passion; that passion, when produc'd, naturally turns the view to a certain object. But this not being sufficient to produce the passion, there is requir'd some other emotion, which by a double relation of impressions and ideas may set these principles in action, and bestow on them their first impulse. This situation is still more remarkable with regard to the appetite of generation. Sex is not only the object, but also the cause of the appetite. We not only turn our view to it, when actuated by that appetite; but the reflecting on it suffices to excite the appetite. But as this cause loses its force by too great frequency, 'tis necessary it shou'd be quicken'd by some new impulse; and that impulse we find to arise from the beauty of the person; that is, from a double relation of impressions and ideas. Since this double relation is necessary where an affection has both a distinct cause, and object, how much more so, where it has only a distinct object, without any determinate cause?