Perutz attacked the theories of philosophers Sir Karl Popper and Thomas Kuhn and biologist Richard Dawkins in a lecture given at Cambridge on 'Living Molecules' in 1994. He criticised Popper's notion that science progresses through a process of hypothesis formation and refutation, saying that hypotheses are not necessarily the basis of scientific research and, in molecular biology at least, they are not necessarily subject to revision either. For Perutz, Kuhn's notion that science advances in paradigm shifts that are subject to social and cultural pressures is an unfair representation of modern science.