premise: In 1920 , the Lambeth Conference repeated its 1908 condemnation of contraception and issued `` an emphatic warning against the use of unnatural <mask> for the avoidance of conception , together with the grave dangers - physical , moral , and religious - thereby incurred , and against the evils which the extension of such use threaten the race '' .
hypothesis: the proper context for <mask> here should be an instrumentality for accomplishing some end