When we sympathize only with one impression, and that a painful one, this sympathy is related to anger and to hatred, upon account of the uneasiness it conveys to us.

But as the extensive or limited sympathy depends upon the force of the first sympathy; it follows, that the passion of love or hatred depends upon the same principle.

A strong impression, when communicated, gives a double tendency of the passions; which is related to benevolence and love by a similarity of direction; however painful the first impression might have been.

A weak impression, that is painful, is related to anger and hatred by the resemblance of sensations.

Benevolence, therefore, arises from a great degree of misery, or any degree strongly sympathized with: Hatred or contempt from a small degree, or one weakly sympathized with; which is the principle I intended to prove and explain.
Nor have we only our reason to trust to for this principle, but also experience.