Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
authoritarian, authoritative (adjs.)
These words are markedly different: authoritarian means “requiring unquestioned obedience to authority, dictatorial,” as in His approach to discipline was authoritarian; he would brook no disagreement or discussion whatsoever. Authoritative has no pejorative overtones where it means “reliable, official, well-qualified,” as in She has written the authoritative biography of the poet. The only overlap is in the sense of “being fond of exerting authority,” but authoritarian is much the stronger in that meaning and suggests a less admirable quality.
