xxi.), but also for a thing which we have hitherto regarded without emotion, provided that we deem that it resembles ourselves (as I will show presently).

Thus, we bestow approval on one who has benefited anything resembling ourselves, and, contrariwise, are indignant with him who has done it an injury.
PROP.XXIII.

He who conceives, that an object of his hatred is painfully affected, will feel pleasure.

Contrariwise, if he thinks that the said object is pleasurably affected, he will feel pain.

Each of these emotions will be greater or less, according as its contrary is greater or less in the object of hatred.
Proof .-- In so far as an object of hatred is painfully affected, it is destroyed, to an extent proportioned to the strength of the pain (III.xi.