What is the so-called "infamous thing" that Voltaire refers to in his signature phrase, "Écrasez l'infâme"?

superstitions

Explanation:

Voltaire is the pen name François-Marie Arouet. He was born in 1694. He was a famous French writer, a philosopher and a deist. He established himself as one of the most leading writer of Enlightenment.

His most famous quote or phrase, "Écrasez l'infâme" which means crush the infamous thing. This was in reference to the letter written to Jean le Rond d'Alembert by him where he asks to crush the superstition and asks Jean to love others those who love him. This phrase, "Écrasez l'infâme" became identified with the Voltaire.