Is freedom of speech a necessity in a functional society

Freedom of speech is not necessary in an unfree society, because communication between the different social strata, or between the subjects and the government, is either not necessary, is frowned upon, or is performed through official means (eg., in a feudal society, the peasant directs his complaints to his local unit, and that unit deals with the local feudal master or with the ruler of the land).

send them to therapy or somthing like that

answer; group think;