From a private nature walk to an engrossing novel, humans spend a vast amount of time engaged in solitary activities. However, despite the fact that individual activities are a prevalent part of everyday life, most scholarly research has been devoted to social interaction rather than solitary action. Ira Cohen's Solitary Action fills this intellectual void, identifying and discussing four basic forms of individual action: peripatetics, engrossments, regimens, and reflexives. Cohen explores the differences and similarities among the forms, specifically delving into the structural contrast between behaviors with rigid constraints, such as the game of solitaire, and behaviors which require creativity and spontaneity, such as a solo jazz improvisation. Lucid and relatable, Solitary Action links its arguments with examples from literature, personal narrative, and daily life, shedding light upon the understated significance of individual activities. The book concludes with a discussion of extensive retreats into solitude for religious, aesthetic, and self-restorative experiences, including examples from Thomas Merton and Henry David Thoreau. Ultimately, Cohen's findings promise to inspire new inquiries into the nature of social behavior by opening a new domain of everyday activities to the attention previously reserved for social interaction.