Semanticism is a theory which states that any attempt to persuade people is dishonest. In Richard Weaver's words, “According to the followers of this movement, the duty of anyone using language is to express the ‘facts’ and avoid studiously the use of emotional coloring” (85). Semanticists believe that we should rely on concrete facts and dialectic, not rhetoric, to communicate and determine what actions should be taken.
Weaver argues vehemently against semanticism, saying it reflects "an astonishing naiveté about the nature of language" (85). Semanticists, he says, are unable to uphold even their own standards of objectivity, as evidenced by their frequent use of the phrase "psychological coercion"- a "highly loaded rhetorical term" - to describe their distaste for rhetoric. He suggests that semanticism is driven primarily by a prejudiced political agenda and that relying on dialectic alone could even bring the downfall of society.
Semanticism is discussed briefly in Weaver, Richard "The Cultural Role of Rhetoric.