The “mind” is not inside but “out there” in the social world

Descartes distinguished between the res cogitans and the res extensa. The former referred to the soul or mind and was said to be essentially “a thing which thinks.”1 The latter was the material stuff of the body. It was characterised primarily by the fact of extension: it occupied space and was therefore amenable to measurement. In recent years neuroscientists and cognitive psychologists have argued that this ontological separation of mind and body is no longer tenable.2 The former maintain that mental functions can be fully explained by brain science. The latter make the case for a distinct psychological realm but one whose operations, like those of computer software, are measurable and open to scientific investigation. The res cogitans is illusive no longer. We can map it, scan it, and explain its functions in biological or computational terms.

These ideas have become dominant in medical circles and, in some form or other, have become articles of faith for most doctors, psychiatrists, and psychologists. Contemporary …