Full Idea
Pity is a pain, and is therefore in itself bad; only at the dictation of reason are we able to perform any action, which we know for certain to be good; thus, in a man who lives under the guidance of reason, pity in itself is useless and bad.
Gist of Idea
Pity is a bad and useless thing, as it is a pain, and rational people perform good deeds without it
Source
Baruch de Spinoza (The Ethics [1675], IV Pr 50)
Book Reference
Spinoza,Benedict de: 'Ethics, Improvement of Understanding, Letters', ed/tr. Elwes,R [Dover 1955], p.221
A Reaction
This is the essence of both Kant's and Bentham's views. It is, however, unclear why a wholly rational and unfeeling person should be motivated to prevent other people's pain. It also don't think it follows that because it is painful it is bad.