When a bad deed has been done, it affords satisfaction not only to the sufferer, who for the most part feels the desire of revenge, but also to the perfectly indifferent spectator, to see that he who caused another pain suffers himself a like measure of pain
 Arthur Schopenhauer, The World as Will and Representation (1819). copy citation

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Author Arthur Schopenhauer
Source The World as Will and Representation
Topic satisfaction revenge
Date 1819
Language English
Reference
Note Translated by R. B. Haldane and J. Kemp
Weblink http://www.gutenberg.org/files/38427/38427-h/38427-h.html

Context

“But first I wish at this point to draw attention to two peculiarities of human nature, that might help to make clear how the nature of that eternal justice, and the unity and identity of the will in all its phenomena upon which it rests, is known to every one, at least as an obscure feeling. When a bad deed has been done, it affords satisfaction not only to the sufferer, who for the most part feels the desire of revenge, but also to the perfectly indifferent spectator, to see that he who caused another pain suffers himself a like measure of pain; and this quite independently of the end which we have shown the state has in view in punishment, and which is the foundation of penal law. It seems to me that what expresses itself here is nothing but the consciousness of that eternal justice, which is, nevertheless, at once misunderstood and falsified by the unenlightened mind, for, involved in the principium individuationis, it produces an amphiboly of the concepts and demands from the phenomenon what only belongs to the thing in itself.” source