Alva Noë, a philosopher at UC Berkeley, argues that consciousness remains a mystery because we’ve been looking in the wrong place. In his provocative and lucid new book, Noë writes that scientists have been so eager to locate the mind in the brain that they’ve neglected to consider the possibility that our mind might not be inside our head.

Then where is it? Don’t worry, Noë isn’t an old-fashioned Cartesian dualist: He doesn’t believe that our consciousness is some metaphysical gift from God. Instead, he suggests that who we are and what we know is inseparable from where we are and what we’re doing: “Consciousness is not something the brain achieves on its own,” Noë writes. “Consciousness requires the joint operation of the brain, body and world. … It is an achievement of the whole animal in its environmental context.”

Noë sells this audacious idea with a series of effective metaphors. For instance, he begins the book by comparing consciousness to a dollar bill. He notes that it would be silly to search for the physical correlates of “monetary value.” After all, the meaning of money isn’t in the paper, or the green ink, or the picture of George Washington. Instead, it exists in the institutions and practices that give the paper meaning. Similarly, our awareness of reality doesn’t depend entirely on what’s happening inside the brain, but is a side effect of how we, as individuals, interact with the wider world.

Jonah Lehrer - Out of Our Heads : The Frontal Cortex