Although Osborne’s best-known play is Look Back in Anger (pr. 1956), the drama that epitomized the “angry young man” genre, that topical play remains rooted in the 1960’s. Despite the popularity of The Entertainer (pr., pb. 1957) and the notoriety of Luther (pr., pb. 1961), the play most likely to be considered Osborne’s best is Inadmissible Evidence, which transcends its 1960’s social criticism and portrays the plight of the individual at odds with society. Inadmissible Evidence draws upon Osborne’s previous plays, particularly Look Back in Anger and The Entertainer: Jimmy Porter is also critical of society and does ironically invite the abandonment he fears; Archie Rice also awaits his fate, the tax man—a counterpart of the Law Society. On the other hand, Bill is mature and mainstream, more akin to an audience which feels mediocre, alienated, and persecuted. For many critics, Inadmissible Evidence represents the culmination of Osborne’s considerable talent and the perfect blending of naturalism and experimentation. Osborne excelled at probing the psychological depths of complex, somewhat unappealing characters caught at a crucial point in their lives; the stylized duologues and casting of Inadmissible Evidence permitted him to present an external drama that mirrors the action that occurs within his protagonist’s mind.
Many critics regard Osborne’s later plays as departures from the fusion of form and content of his masterpiece. Inadmissible Evidence was the last play in which one character dominated the action; the play has even been referred to as a “monodrama.” The later plays have muted the anger and intensity of Inadmissible Evidence, and they have not been as successful at incorporating Osborne’s gratuitous social criticism into the dramatic text. Inadmissible Evidence, despite the topicality of its specific criticism, remains a play thoroughly modern and universal in its protagonist and its conflict between the individual and an impersonal yet paradoxically hostile society.