Think of psychology and its foundation. What comes to mind? Probably names such as Freud, Jung, Pavlov, Vygotsky, but this list is by no means valid without the name of Jean Piaget. The swiss psychologist, the creator of the theory of cognitive development, object permanence and schemas, is arguably the greatest psychologist of history.  

His 1926 work, The Childs Conception Of The World, examines how the child reasons with the world. How does the child actually perceive causality, law and external reality? How does the child distinguish between the self and the external? Is the childs mind similar to adults or does the child perceive the reality and the world much different then the more experienced mind of an adult?