''Letter on the Deaf and Dumb, for the Use of those who hear and speak'' (French: ''Lettre sur les sourds et muets a l'usage de ceux qui entendent et qui parlent'') is a work by

Denis Diderot Denis Diderot (; ; 5 October 171331 July 1784) was a French philosopher, art critic, and writer, best known for serving as co-founder, chief editor, and contributor to the '' Encyclopédie'' along with Jean le Rond d'Alembert. He was a promi ...

containing a psychological investigation on the

deaf-mute Deaf-mute is a term which was used historically to identify a person who was either deaf and used sign language or both deaf and could not speak. The term continues to be used to refer to deaf people who cannot speak an oral language or have som ...

. It was published in 1751. It was meant to be a companion volume to Diderot's Letter on the Blind.

Content

The book consists of an enquiry into the method of communication used by deaf-mutes, and seeks to shed light on the origin of language by observing the gestures, and response to gestures, of deaf-mutes.

References

{{Authority control Denis Diderot