To do otherwise is to waste one's existence. Thoreau wrote in Walden that many of the people one sees on the street are human in form only, and are not actually human beings in the strictest sense. There is a sure-fire way to become one of the people Thoreau criticized.
自然生活的經典之作《湖濱散記》裡，梭羅曾經說過，許多在街上行走的人徒具人的外型，其實嚴格的說，並不能算是人。