"Koestler uses the metaphor of Janus, a two-faced Roman God, to represent the polarity of a holon. The face that points in towards its subordinate parts is that of the whole; while the face pointing upwards towards the apex is that of a dependent part. As a whole, a human being is intrinsically an autonomous, self-contained unit, made of levels of subsystems inside its body. Extrinsically, it is part of a social community, a state; something bigger than itself, to which it contributes. This polarized phenomenon of a holon is called the Janus Principle."