Along with Georges Berkeley and David Hume, John Locke (1632-1704) is one of the great masters of British empiricism. Although his writings were read extensively particularly by Voltaire this great philosopher has since been consigned to a relative (and unjust) oblivion. The increasing popularity of cognitivism in Anglo-Saxon circles has inspired renewed interest in Locke ; it therefore seems appropriate to showcase his work in a " continental " setting.Basing his findings on Locke's famous work, Essay Concerning Human Understanding (1690), Alexis Tadié successively examines Locke's theory of ideas, abstraction, distinction between primary and secondary qualities, concept of substance, causality and power, identity, language, and the nature of knowledge and skepticism. He also presents two major interpretations of Locke's philosophy, from the writings of Berkeley and Leibnitz.Alexis Tadié, who holds an agrégation degree is in Philosophy, was formerly the French cultural attaché to the Syrian Arab Republic. He is currently a researcher at the CNRS.