"The light touch of a hairdresser's hands on one's scalp, the euphoric energy of a nightclub, huddling with strangers under a shelter in the rain, a spontaneous snowball fight in the street, a daily interaction with a homeless man--such mundane connections, when we closely inhabit the same space, and touch or are touched by others, were nearly lost to "social distancing." Will we ever again shake hands without a thought? In this deeply rewarding book,...