Karl Groos's The Play of Man is a wide-ranging scholarly study of human play, introduced by J. Mark Baldwin as a major companion to Groos's earlier work on animal play. Groos sets out to classify play through "impulse life," arguing that existing systems are inadequate and that play must be understood as instinctive practice shaping development, adaptation, and culture. The book moves from sensory and motor play to higher mental activity, social impulses, and finally to broad theories of play from physiological, psychological, aesthetic, sociological, and pedagogical viewpoints. Its chapters trace playful experimentation from infancy through adulthood: grasping, sucking, touching, tasting, smelling, fidgeting, dancing, bathing, and delight in the body's contact with the world. Groos shows how such pleasures train the senses, build coordination, and leave lasting traces in habits, customs, and artistic feeling. He then turns to teasing, mockery, mimicry, satire, caricature, and scornful song, revealing play's unstable border with cruelty, wit, and social dominance. This edition has been fully restored with modern typesetting, custom cover design.