The only explication, then, we can give of this phaenomenon is derived from that principle of a parallel direction above-mentioned.  Our concern for our own interest gives us a pleasure in the pleasure, and a pain in the pain of a partner, after the same manner as by sympathy we feel a sensation correspondent to those, which appear in any person, who is present with us.  On the other hand, the same concern for our interest makes us feel a pain in the pleasure, and a pleasure in the pain of a rival; and in short the same contrariety of sentiments as arises from comparison and malice.  Since, therefore, a parallel direction of the affections, proceeding from interest, can give rise to benevolence or anger, no wonder the same parallel direction, derived from sympathy and from comparison, should have the same effect.

In general we may observe, that it is impossible to do good to others, from whatever motive, without feeling some touches of kindness and good-will towards them; as the injuries we do, not only cause hatred in the person, who suffers them, but even in ourselves.  These phaenomena, indeed, may in part be accounted for from other principles.

But here there occurs a considerable objection, which it will be necessary to examine before we proceed any farther.  I have endeavoured to prove, that power and riches, or poverty and meanness; which give rise to love or hatred, without producing any original pleasure or uneasiness; operate upon us by means of a secondary sensation derived from a sympathy with that pain or satisfaction, which they produce in the person, who possesses them.  From a sympathy with his pleasure there arises love; from that with his uneasiness, hatred.  But it is a maxim, which I have just now established, and which is absolutely necessary to the explication of the phaenomena of pity and malice, that it is not the present sensation or momentary pain or pleasure, which determines the character of any passion, but the general bent or tendency of it from the beginning to the end.  For this reason, pity or a sympathy with pain produces love, and that because it interests us in the fortunes of others, good or bad, and gives us a secondary sensation correspondent to the primary; in which it has the same influence with love and benevolence.  Since then this rule holds good in one case, why does it not prevail throughout, and why does sympathy in uneasiness ever produce any passion beside good-will and kindness?  Is it becoming a philosopher to alter his method of reasoning, and run from one principle to its contrary, according to the particular phaenomenon, which he would explain?

I have mentioned two different causes, from which a transition of passion may arise, viz, a double relation of ideas and impressions, and what is similar to it, a conformity in the tendency and direction of any two desires, which arise from different principles.  Now I assert, that when a sympathy with uneasiness is weak, it produces hatred or contempt by the former cause; when strong, it produces love or tenderness by the latter.  This is the solution of the foregoing difficulty, which seems so urgent; and this is a principle founded on such evident arguments, that we ought to have established it, even though it were not necessary to the explication of any phaenomenon.