This introduction revisits the enduring binary of nature and nurture, tracing its roots from ancient Greek sophistic thought to contemporary scientific and philosophical debates. Using the Sphinx’s riddle as a metaphorical point of departure, it poses the central enigma of human nature and interrogates what it truly means to be human. Across cultures and historical periods, humanity has been interpreted through binary oppositions—sacred and profane, body and soul, reality and illusion—yet few have remained as persistent or divisive as the nature/nurture divide. This volume examines how human traits such as aggression, love, and morality have been explained through both biological determinism and radical social constructionism, and how both perspectives have been alternately sacralized or challenged by different ideological camps. While the volume does not claim to definitively resolve the deeper riddle posed by the Sphinx, it offers a rigorous, pluralistic, and multidisciplinary approach to the question of human nature—understood as neither fixed nor entirely malleable, but shaped by a complex and evolving interplay of dimensions and variables.