John Locke (1632-1704) was a philosopher whose ideas were early precursors to many important psychological concepts. John Locke introduced the concept of tabula rasa which is the belief that the mind is a 'blank slate' at birth and we are formed and develop from our own experiences with the environment. He was a devout believer in the 'nurture' side of the "nature versus nurture" debate because of his belief that all behavior, inclinations, and thought patterns were learned, rather than inherent. This was one of the earliest ideas that is used for the basis of behaviorism. Locke believed that the experience that occurred in the early childhood years was the most important and influential on a person. He stressed the importance of rewards and punishments in social learning. Locke also introduced the concept of the social contract theory.