A key figure in the history of Psychology, Jean Piaget, grappled with an issue that remains important today – understanding human development without reducing it to genetic determinism or socialization. Piaget articulated a constructivist theory of how infants and children develop increasingly complex and abstract means of understanding aspects of the world. These extend from elementary physics to mathematics to social and moral issues. Given that humans share many experiences, development has similarities across individuals and cultures. Piaget thus suggested a series of stages that depict these achievements. While highly influential in the 1950s and 60s, his theory became a focus of attack from within developmental psychology, largely from positions that Piaget had set out to demonstrate as being flawed. While largely misrepresented in contemporary texts of child development, the theory has much to offer contemporary and future accounts of human development.