Hilary Whitehall Putnam (July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, and computer scientist who was a central figure in analytic philosophy from the 1960s, especially in philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science. He was known for his willingness to apply an equal degree of scrutiny to his own philosophical positions as to those of others, subjecting each position to rigorous analysis until he exposed its flaws. As a result, he acquired a reputation for frequently changing his own position. At the time of his death, Putnam was Cogan University Professor Emeritus at Harvard University.