Ned Block (born 1942) is an American philosopher working in the field of the philosophy of mind who has made important contributions to matters of consciousness and cognitive science. In 1971, he obtained his Ph.D. from Harvard University under Hilary Putnam. He went to Massachusetts Institute of Technology (MIT) as an assistant professor of philosophy (1971-1977), worked as associate professor of philosophy (1977-1983), professor of philosophy (1983-1996) and served as chair of the philosophy section (1989-1995). He has, since 1996, been a professor in the departments of philosophy and psychology and at the Center for Neural Science at New York University (NYU).
Block is noted for presenting the Blockhead argument against the Turing Test as a test of intelligence in a paper entitled Psychologism and Behaviourism (1981). He is also known for his criticism of functionalism, arguing that a system with the same functional states as a human is not necessarily conscious. In his more recent work on consciousness, he has made a distinction between phenomenal consciousness and access consciousness, where phenomenal consciousness consists of subjective experience and feelings and access consciousness consists of that information globally available in the cognitive system for the purposes of reasoning, speech and high-level action control. He has argued that access consciousness and phenomenal consciousness might not always coincide in human beings.
Block has been a judge at the Loebner Prize contest, a contest in the tradition of the Turing Test to determine whether a conversant is a computer or a human.
He is married to the developmental psychologist Susan Carey.