Psychologists have been intensely interested for several decades in the two modes of thinking evoked by the picture of the angry woman and by the multiplication problem, and have offered many labels for them. I adopt terms originally proposed by the psychologists Keith Stanovich and Richard West, and will refer to two systems in the mind, System 1

The human mind perceives, forms concepts, learns, makes judgements, feels emotions, uses language, remembers, invents, dreams, desires. How can so much complexity be captured in a single image? Clearly, some aspects of mental life must be prioritised at the expense of others. But which ones? And after those choices have been made, does the 'picture

even among audiences whose work involves diagnosing, understanding, or changing mental processes, only a tiny percentage have ever learned what a mind is.