Who said "The object of conversation is to please and to instruct."?

This quote is attributed to Denis Diderot.

The object of conversation is to please and to instruct. - Denis Diderot

"The object of conversation is to please and to instruct."

Denis Diderot

Philosopher Writer French 1713–1784

"The world is for those who think."

"Man will never be free until the last king is strangled with the entrails of the last priest."

"Nothing can be believed unless it is seen."

"I am convinced the mind can be developed to the point where success is inevitable."