is pleasure accompanied by the idea of an external cause, and hatred is pain accompanied by the idea of an external cause
 Baruch Spinoza, Ethics (1677). copy citation

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Author Baruch Spinoza
Source Ethics
Topic pain pleasure
Date 1677
Language English
Reference
Note Translated by R. H. M. Elwes
Weblink http://www.gutenberg.org/files/3800/3800-h/3800-h.htm

Context

“is conscious of himself through the modifications whereby he is determined to action, it follows that he who conceives, that he affects others pleasurably, will be affected with pleasure accompanied by the idea of himself as cause; in other words, he will regard himself with pleasure. And so mutatis mutandis in the case of pain. Q.E.D. Note.—As love (III. xiii.) is pleasure accompanied by the idea of an external cause, and hatred is pain accompanied by the idea of an external cause; the pleasure and pain in question will be a species of love and hatred. But, as the terms love and hatred are used in reference to external objects, we will employ other names for the emotions now under discussion:” source