On the other hand, Stewart has been described as a character actor who went through several distinct career phases. According to film scholar Amy Lawrence, the main elements of Stewart's persona "a propensity for physical and spiritual suffering, lingering fears of inadequacy," were established by Frank Capra in the 1930s and were enhanced through his later work with Hitchcock and Mann. John Belton explained that "James Stewart evolves from the naive, small-town, populist hero of Frank Capra's 1930s comedies to the bitter, anxiety-ridden, vengeance-obsessed cowboy in Anthony Mann's 1950s Westerns and the disturbed voyeur and sexual fetishist in Alfred Hitchcock's 1950s suspense thrillers." During his postwar career, Stewart avoided appearing in comedies, "Harvey" being the exception. He played many different types of characters, including manipulative, cynical, obsessive, or crazy characters. Stewart found that acting allowed him to express the fear and anxiety that he could not express during the war; his post-war performances were received well by audiences because audiences could still see the innocent, pre-war Stewart underneath his dark roles. According to Andrew Sarris, Stewart was "the most complete actor-personality in the American cinema."