It would make an interesting essay or monograph to descrbibe the various similes and metaphors that people have variously used to describe the working of the human mind. Descartes, I believe, thought the brain worked via a series of hydraulics, and the Victorians thought that it worked by some variant of electricity, both of these being "new" and possibly exciting technologies for their times. Notwithstanding the scientific versimillitude of these previous theories, it seems only fitting that computers occupy that role today.