Because they feel themselves unhappy, men cannot endure the sight of one whom they imagine happy
 Arthur Schopenhauer, The World as Will and Representation (1819). copy citation

add
Author Arthur Schopenhauer
Source The World as Will and Representation
Topic sight feeling
Date 1819
Language English
Reference
Note Translated by R. B. Haldane and J. Kemp
Weblink http://www.gutenberg.org/files/40868/40868-h/40868-h.html

Context

“An indirect but certain proof of the fact that men feel themselves unhappy, and consequently are so, is also abundantly afforded by the fearful envy which dwells in us all, and which in all relations of life, on the occasion of any superiority, of whatever kind it may be, is excited, and cannot contain its poison. Because they feel themselves unhappy, men cannot endure the sight of one whom they imagine happy; he who for the moment feels himself happy would like to make all around him happy also, and says: “Que tout le monde ici soit heureux de ma joie.” If life were in itself a blessing to be prized, and decidedly to be preferred to non-existence, the exit from it would not need to be guarded by such fearful sentinels as death and its terrors.” source