Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
consensus (of opinion)
There are two usage problems: (1) Concensus is an obsolete variant spelling of consensus and is now considered a misspelling; avoid it. (2) Consensus, many commentators insist, already means “an agreement among holders of opinion,” so consensus of opinion must be redundant. Not entirely so: there are many kinds of consensus that do not involve opinion—consensus of political forces, of military tactics, of ordinances, of evidence, and the like. Actually, consensus (of opinion) is in divided usage; its chief flaw is a matter of style: it is not as concise as some would wish. Use it if you will, but if you do, be aware that some people will judge you ignorant on what they are sure is a blunder in usage. General consensus, however, is almost always redundant; avoid it. Compare COURSE OF.
