H.L.A. Hart was a prominent British legal philosopher, best known for his contributions to the field of legal positivism. Born in 1907, he served as a professor of jurisprudence at the University of Oxford and published influential works, including "The Concept of Law" in 1961. Hart's ideas focused on the relationship between law, morality, and society, emphasizing the importance of legal systems. Hart is often associated with the debate against natural law theorists, particularly in his discussions with Ronald Dworkin. He argued that laws are rules created by human beings and that their validity is not dependent on moral considerations. His work has had a lasting impact on legal theory and philosophy.