In western thought there has been a venerable tradition in which the mind has been conceived of in terms of distinct faculties. Scholastic thought in the Middle Ages, associated most notably with the theologian Thomas Aquinas, proposed that mental functions were attributes of specific parts of the mind. With the advent of cognitive science in the 1950s, the digital computer became the analogy of choice for the human mind. Computers, like human brains, appeared to constitute a mechanism capable of complex reasoning. Cognitive science took the computational processes deployed by computers as an analogy for how the brain computes the mind. In the mind-as-computer metaphor, the information processing performed by computers is much like human cognition.