A Treatise of Human Nature by David Hume — Read

It is altogether impossible to give any definition of the passions of love and hatred; and that because they produce merely a simple impression, without any mixture or composition. Twould be as unnecessary to attempt any description of them, drawn from their nature, origin, causes and objects; and that both because these are the subjects of our present enquiry, and because these passions of themselves are sufficiently known from our common feeling and experience. This we have already observed concerning pride and humility, and here repeat it concerning love and hatred; and indeed there is so great a resemblance betwixt these two sets of passions, that we shall be obliged to begin with a kind of abridgment of our reasonings concerning the former, in order to explain the latter.

As the immediate object of pride and humility is self or that identical person, of whose thoughts, actions, and sensations we are intimately conscious; so the object of love and hatred is some other person, of whose thoughts, actions, and sensations we are not conscious. This is sufficiently evident from experience. Our love and hatred are always directed to some sensible being external to us; and when we talk of self-love, it is not in a proper sense, nor has the sensation it produces any thing in common with that tender emotion which is excited by a friend or mistress. It is the same case with hatred. We may be mortified by our own faults and follies; but never feel any anger or hatred except from the injuries of others.