As to fidelity, there is no animal in the world so treacherous as man.
 Michel de Montaigne, The Essays of Michel de Montaigne (1580). copy citation

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Author Michel de Montaigne
Source The Essays of Michel de Montaigne
Topic fidelity animal
Date 1580
Language English
Reference
Note Translated by Charles Cotton
Weblink http://www.gutenberg.org/files/3600/3600-h/3600-h.htm

Context

“the same reason that makes us whip a lackey, falling into the hands of a king makes him ruin a whole province. They are as lightly moved as we, but they are able to do more. In a gnat and an elephant the passion is the same. As to fidelity, there is no animal in the world so treacherous as man. Our histories have recorded the violent pursuits that dogs have made after the murderers of their masters. King Pyrrhus observing a dog that watched a dead man’s body, and understanding that he had for three days together performed that office, commanded that the body should be buried, and took the dog along with him.” source