Written before the "problem comedies" such as Troilus and Cressida and Measure for Measure, Twelfth Night marks for many critics the most well-crafted of Shakespeare's "happy comedies," one rich in symbolism and complex in its exploration of love, its blurring of appearance and reality, its troubling of gender, and its portrayal of human psychology.
As in most of Shakespeare's romantic comedies from the 1590's, love motivates many of the characters' actions and attitudes. Some commentators, such as Peter G. Phialas (1966) and Charles Tyler Prouty (1966), have claimed that the characters interact in order to depict a Renaissance ideal of courtly love. Richard Henze (1975) has expanded this line of thought, arguing that Shakespeare resolves the play's contradictions through the interaction of characters, particularly through love-relationships. Similarly, Dennis R. Preston (1970) has asserted that the minor characters bind the seemingly disparate elements of the play, forming a unified whole. Other critics, including Terence Eagleton (1967), have contended that love in the play fuses language and reality, and thus questions the fixity of nature.
While some scholars have argued that love is the primary subject of Twelfth Night and have debated whether it has a unifying or dissembling effect on the dichotomy between appearance and reality, other commentators have identified this very dichotomy as the play's central theme. For example, Karen Greif (1981) has focused on Shakespeare's questioning of the nature of truth through the characters' "play," claiming that "Twelfth Night poses questions about 'the purpose of playing' and about whether illusion is perhaps too deeply embedded in human experience to be ever completely separated from reality." Other critics, including D. J. Palmer (1967), have contextualized Shakespeare within a tradition that conflates art and nature, and Walter N. King (1968), drawing on the history of philosophy, has considered Shakespeare to be consciously commenting on a Parmenidean approach to metaphysics. The resulting portrayal of nature has led commentators such as Karin S. Coddon (1993) to consider Twelfth Night as questioning the stability of social status by troubling a supposedly natural hierarchy in Elizabethan society.
In addition to Shakespeare's problematizing the fixity of nature, many feminist literary theorists have claimed that disorder in Twelfth Night also affects definitions of sex and gender, focusing primarily on the Viola/ Cesario character. Scholars have extensively debated whether Shakespeare consciously or unconsciously uses Viola's role-playing to demonstrate the plasticity of socially constructed gender roles as well as whether the character calls supposedly fixed sexual differences into question. Stevie Davies (1993) and Nancy Hayles (1979), for example, have contended that Viola's role-playing questions the idea of a naturally determined gender. Others, such as Lorna Hutson (1996), have argued that Shakespeare affirms not only the plasticity of gender, but the rhetorical construction of sex as well.
Modern commentators have also studied the tenets of psychoanalysis to explore both the actions of the characters and the motivations of the author. Freudian and Jungian taxonomies have been used to dissect characters' actions (such as Viola's putting on the guise of a man) and their personification of psychological attributes. For example, Helene Moglen (1973) has contended that Twelfth Night portrays a psychological picture "strikingly similar to major aspects of Freud's own theory of psycho-sexual development." Critics such as Leonard F. Manheim (1964) have even applied psychoanalytic theory to Shakespeare himself, finding in Twelfth Night an expression of his unconscious attempt to enact an Oedipal fantasy.
Critical approaches to Twelfth Night have varied considerably, from strict examinations of the text alone to psychoanalytic evaluations of its author, from historical inquiries into Elizabethan love to feminist interpretations of sex and gender. Regardless, Twelfth Night continues to attract contemporary criticism, as commentators find in the play the height of Shakespeare's comedic art.