Twill be sufficient to remark in general, that the object of love and hatred is evidently some thinking person; and that the sensation of the former passion is always agreeable, and of the latter uneasy.

We may also suppose with some shew of probability, THAT THE CAUSE OF BOTH THESE PASSIONS IS ALWAYS RELATED TO A THINKING BEING, AND THAT THE CAUSE OF THE FORMER PRODUCE A SEPARATE PLEASURE, AND OF THE LATTER A SEPARATE UNEASINESS.
One of these suppositions, viz, that the cause of love and hatred must be related to a person or thinking being, in order to produce these passions, is not only probable, but too evident to be contested.

Virtue and vice, when considered in the abstract; beauty and deformity, when placed on inanimate objects; poverty and riches when belonging to a third person, excite no degree of love or hatred, esteem or contempt towards those, who have no relation to them.

A person looking out at a window, sees me in the street, and beyond me a beautiful palace, with which I have no concern: I believe none will pretend, that this person will pay me the same respect, as if I were owner of the palace.
It is not so evident at first sight, that a relation of impressions is requisite to these passions, and that because in the transition the one impression is so much confounded with the other, that they become in a manner undistinguishable.

But as in pride and humility, we have easily been able to make the separation, and to prove, that every cause of these passions, produces a separate pain or pleasure, I might here observe the same method with the same success, in examining particularly the several causes of love and hatred.