A form of holism according to which the world consists of organisms (or holons or morphic units, q.v.) at all levels of complexity. Organisms are wholes made up of parts, which are themselves organisms, and so on; they are organized in nested hierarchies. The parts of organisms can be understood only in relation to their activities and functions in the ongoing whole. Organisms in this sense include atoms, molecules, crystals, cells, tissues, organs, plants and animals, societies, cultures, ecosystems, planets, planetary systems, and galaxies. In this spirit, the entire cosmos can be regarded as an organism rather than a machine (cf. mechanistic theory).