In 1998, the philosophers Andy Clark and David Chalmers published a paper entitled The Extended Mind . There, they argued that external objects – books, computers and smartphones – spread cognitive processes beyond the boundaries of the individual mind, becoming (literally) part of the mind itself. And with that, the idea of "active externalism" or “extended cognition” was born. Sound bizarre? The idea, though it flies in the face of our intuitions, feels strangely compelling