Every social occurrence as such, consists of an interaction between individuals. In other words, each individual is at the same time an active and a … - Georg Simmel

Der Fremde ist uns nah, insofern wir Gleichheiten nationaler oder sozialer, berufsmäßiger oder allgemein menschlicher Art zwischen ihm und uns fühlen; er ist uns fern, insofern diese Gleichheiten über ihn und uns hinausreichen und uns beide nur verbinden, weil sie überhaupt sehr Viele verbinden.

All relationships of people to each other rest, as a matter of course, upon the precondition that they know something about each other. The merchant knows that his correspondent wants to buy at the lowest price and to sell at the highest price. The teacher knows that he may credit to the pupil a certain quality and quantity of information. Within each social stratum the individual knows approximately what measure of culture he has to presuppose in each other individual.

Every relationship between two individuals or two groups will be characterized by the ratio of secrecy that is involved in it. Even when one of the parties does not notice the secret factor, yet the attitude of the concealer, and consequently the whole relationship, will be modified by it.