Egoism consists really in the fact that man limits all reality to his own person, in that he imagines that he lives in this alone and not in others.
 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 reality egoism
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

“and it may be conceived as a punishment for our existence.32 It is the painful loosing of the knot which the act of generation had tied with sensual pleasure, the violent destruction coming from without of the fundamental error of our nature: the great disillusion. We are at bottom something that ought not to be: therefore we cease to be. Egoism consists really in the fact that man limits all reality to his own person, in that he imagines that he lives in this alone and not in others. Death teaches him better, for it destroys this person, so that the true nature of man, which is his will, will henceforth live only in other individuals; while his intellect, which itself belonged only to the phenomenon, i.e., to the world as idea, and was merely the form of the external world, also continues to exist in the condition of being idea, i.e., in the objective being of things as such, thus also only in the existence of what was hitherto the external world.” source