In 1908 the sociologist Georg Simmel published a long chapter on the secret in his book Soziologie. He described an ideal sphere around every person. The further a person stands from the center of our personality, he wrote, the more easily we accept that they do not tell us the truth. Of an acquaintance, Simmel said that he knows that we are, not what we are. Die Kenntnis des »Daß«, nicht des »Was« der Persönlichkeit bedingt die »Bekanntschaft«. He defined discretion as the sense of what is right toward the sphere of another person’s immediate life.