He who will know fully the vanity of man has only to consider the causes and effects of love.
 Blaise Pascal, Pensées (1670). copy citation

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Author Blaise Pascal
Source Pensées
Topic vanity love
Date 1670
Language English
Reference
Note Translated by W. F. Trotter
Weblink http://www.gutenberg.org/files/18269/18269-h/18269-h.htm

Context

“Now only mastery and sovereignty bring glory, and only slavery brings shame. 161 Vanity.—How wonderful it is that a thing so evident as the vanity of the world is so little known, that it is a strange and surprising thing to say that it is foolish to seek greatness! 162 He who will know fully the vanity of man has only to consider the causes and effects of love. The cause is a je ne sais quoi (Corneille) , [76] and the effects are dreadful. This je ne sais quoi, so small an object that we cannot recognise it, agitates a whole country, princes, armies, the entire world.” source