This hypothesis is founded on sufficient experience. A man, who, from any motives, has entertained a resolution of performing an action, naturally runs into every other view or motive which may fortify that resolution, and give it authority and influence on the mind. To confirm us in any design, we search for motives drawn from interest, from honour, from duty. What wonder, then, that pity and benevolence, malice and anger, being the same desires arising from different principles, should so totally mix together as to be undistinguishable? As to the connexion betwixt benevolence and love, anger and hatred, being _original_ and primary, it admits of no difficulty. We may add to this another experiment, viz. that benevolence and anger, and, consequently, love and hatred, arise when our happiness or misery have any dependence on the happiness or misery of another person, without any farther relation. I doubt not but this experiment will appear so singular as to excuse us for stopping a moment to consider it. Suppose that two persons of the same trade should seek employment in a town that is not able to maintain both, 'tis plain the success of one is perfectly incompatible with that of the other; and that whatever is for the interest of either is contrary to that of his rival, and so _vice versa_. Suppose, again, that two merchants, though living in different parts of the world, should enter into co-partnership together, the advantage or loss of one becomes immediately the advantage or loss of his partner, and the same fortune necessarily attends both. Now, 'tis evident, that, in the first case, hatred always follows upon the contrariety of interests; as, in the second, love arises from their union. Let us consider to what principle we can ascribe these passions. 'Tis plain they arise, not from the double relations of impressions and ideas, if we regard only the present sensation. For, taking the first case of rivalship, though the pleasure and advantage of an antagonist necessarily causes my pain and loss, yet, to counterbalance this, his pain and loss causes my pleasure and advantage; and, supposing him to be unsuccessful, I may, by this means, receive from him a superior degree of satisfaction. In the same manner the success of a partner rejoices me, but then his misfortunes afflict me in an equal proportion; and 'tis easy to imagine that the latter sentiment may, in some cases, preponderate. But whether the fortune of a rival or partner be good or bad, I always hate the former and love the latter.