Holon

A holon (Greek: ὅλον, from ὅλος, holos, 'whole' and -ον, -on, 'part') is something that is simultaneously a whole in and of itself, as well as a part of a larger whole.[1] In other words, holons can be understood as the constituent part–wholes of a hierarchy.

The holon represents a way to overcome the dichotomy between parts and wholes, as well as a way to account for both the self-assertive and the integrative tendencies of organisms. The term was coined by Arthur Koestler in The Ghost in the Machine (1967). In Koestler's formulations, a holon is something that has integrity and identity while simultaneously being a part of a larger system; it is a subsystem of a greater system.

The title of Koestler's book points to the notion that the entire 'machine' of life and of the universe itself is ever-evolving toward more and more complex states, as if a ghost were operating the machine.

(Source: Wikipedia)