First Sentence

"KNOWING THAT IT is possible to see too much, most doormen in New York have developed and extraordinary sense of selective vision: they know what to see and what to ignore, when to be curious and when to be indolent; they are most often standing indoors, unaware, when there are accidents or arguments in front of their buildings; and they are usually in the street seeking taxicabs when burglars are escaping through the lobby."