Ancient philosophers are often contrasted with contemporary philosophers because they view philosophy not as a profession but as a way of life. None did so more uncompromisingly than Diogenes the Cynic, who chided even Socrates for occasionally wearing sandals and maintaining a small household. Diogenes’s espousal of extreme poverty, talent for exhibitionism, and propensity for offense were taken by some to be merely childish and grounded in a desire for fame, but by others as an ideal form of pure philosophical commitment. Beginning with his life as a banker’s son in Sinope, this book traces his exile and status as a foreigner in Athens and Corinth, his subsequent embrace of a life of poverty, and his development of a style of life that both he and others found comparable to a dog’s in its disregard for social norms and conventions. Much of Diogenes’s practical philosophy took the form of his own distinctive bodily practices, which were meant to reinforce Cynic freedom and self-sufficiency. By calling into question cultural conventions governing the body with respect to sexuality, athletics, clothing, hygiene, punishment, et cetera, his own doggish life championed unrestrained free speech (parrhēsia), equality between the sexes, and a cosmopolitan view of the possibilities of a world rid of the evils caused by the pursuit of wealth, fame, and power. Throughout various historical periods, Diogenes has offered a fascinating alternative to conventional lives and served as a brave exemplar of absolute devotion to human freedom and equality.