If at large gatherings or parties, or around people with whom you feel distant, your hands sometimes hang awkwardly at the ends of your arms—if you find yourself at a loss for what to do with them, overcome with sadness that comes when you recognize the foreignness of your own body—it’s because your hands remember a time when the division between mind and body, brain and heart, what’s inside and what’s outside, was so much less. It’s not that we’ve forgotten the language of gestures entirely. The habit of moving our hands while we speak is left over from it. Clapping, pointing, giving the thumbs-up: all artifacts of ancient gestures. Holding hands, for example, is a way to remember how it feels to say nothing together. And at night, when it’s too dark to see, we find it necessary to gesture on each other’s bodies to make ourselves understood.