David Deutsch, FRS is a British physicist at the University of Oxford. He is a non-stipendiary Visiting Professor in the Department of Atomic and Laser Physics at the Centre for Quantum Computation (CQC) in the Clarendon Laboratory of the University of Oxford. He pioneered the field of quantum computation by being the first person to formulate a description for a quantum Turing machine, as well as specifying an algorithm designed to run on a quantum computer. He is also a proponent of the many-worlds interpretation of quantum mechanics.In his books, he also made philosophical contributions. In epistemology, he stressed the importance of explanation, and proposed 'hard to vary' as a criterion for good explanations. In memetics, he gave an account of how memes work, separating them into 'dynamic' or rational memes and 'static' or anti-rational memes. He also advocates optimism, potentially boundless progress, objective beauty in aesthetics, and reason.