An organization comes into being when (1) there are persons able to communicate with each other (2) who are willing to contribute action (3) to accomplish a common purpose. The elements of an organization are therefore (1) communication; (2) willingness to serve; and (3) common purpose. These elements are necessary and sufficient conditions initially, and they are found in all such organizations. The third element, purpose, is implicit in the definition. Willingness to serve, and communication, and the interdependence of the three elements in general, and their mutual dependence in specifie cooperative systems, are matters of experience and observation.