(n.) One who theorizes or speculates; a theorist.

antiblack armchair authority authoritarian authoritative biased bigot bigoted bullheaded chauvinist chauvinistic colored conceited doctrinarian dogged dogmatic dogmatist dogmatizer dogmatizing fanatic hypothesist hypothesizer illiberal infallibilist influenced interested intolerant jaundiced jingo know-nothing magisterial male chauvinist mulish nonobjective obstinate one-sided opinionated opinionative opinioned opinionist oracular partial partisan peremptory pertinacious pig pigheaded pontifical positive positivist positivistic prejudiced prepossessed pronunciative racist self-opinionated self-opinioned sexist speculator stiff-necked stubborn superpatriot superpatriotic swayed theoretic theoretician theorist theorizer twisted ultranationalist undetached undispassionate warped xenophobic