What Do You Call A Person Who Doubts Everything?

What Do You Call A Person Who Doubts Everything? skeptic. / (ˈskɛptɪk) / What is a doubtful person? unsettled in opinion or belief; undecided; hesitating. of equivocal or questionable character: His tactics are highly doubtful. What do you call someone who doubts themselves? as in insecurity, diffidence. Synonyms & Near Synonyms for self-doubt. diffidence, insecurity,