The Invisible HandHow the "invisible hand" of the nervous system makes the human hand such an evolutionary success. The hand has a central role in both human evolution and cultural developmentin our descent and in our ascent. It is, Immanuel Kant said, "the visible part of the brain." It is the invisible that concerns Matthew Longo in The Invisible Hand, a wide ranging, deftly written account of the neural and cognitive mechanisms that have made a seemingly ordinary