John Locke (1632-1704) was an English philosopher, physician and one of the most influential of Enlightenment thinkers. One of the first of the British empiricists he is important to social contract theory. His work had a great impact upon the development of epistemology and political philosophy. His writings influenced Voltaire and Rousseau. His contributions to classical republicanism and liberal theory are reflected in the American Declaration of Independence. Locke's theory of mind is often cited as the origin of modern conceptions of identity and the self. Locke was the first to define the self through a continuity of consciousness. He postulated that the mind was a blank slate or tabula rasa. He believed we are born without innate ideas, and that knowledge is instead determined by experience derived from sense perception. Locke never married nor had children. He died at the age of 72.