Cette citation est extraite du 'Dictionnaire philosophique' de Voltaire, publié en 1764, dans l'article 'Beau' où il discute de la relativité des notions esthétiques.
"Ask a toad what beauty is: he will answer that it is his toad with two big round eyes bulging from his little head... Question the devil and he will tell you that beauty is a pair of horns, four claws and a tail."