An integrative level, or level of organization, is a set of phenomena emerging from pre-existing phenomena of a lower level. The levels concept is an intellectual framework for structuring reality. It arranges all material entities and all processes in the universe into a hierarchy based on how complex the entity's organization is. When arranged this way, each entity is three things at the same time: It is made up of parts from the previous level below. It is a whole in its own right. And it is a part of the whole that is on the next level above. Typical examples include life emerging from non-living substances, and consciousness emerging from nervous systems.
The main levels usually acknowledged are those of matter, life, mind, and society. These are called strata in Nicolai Hartmann's ontology. They can be further analyzed into more specific layers, such as those of particles, atoms, molecules, and rocks forming the material stratum, or those of cells, organisms, populations, and ecosystems forming the life stratum.
The sequence of levels is often described as one of increasing complexity, although it is not clear whether this is always true: for example, parasitism emerges on pre-existing organisms, although parasites are often simpler than their originating forms.
Ideas connected to integrative levels can be found in the works of both materialist philosophers, and anti-materialist ones.
- Alexander, Samuel, Space, time and deity, London, 1920
- Blitz, D., Emergent evolution: qualitative novelty and the levels of reality, Kluwer, 1992
- Conger, G.P., "The doctrine of levels", Journal of philosophy, 22: 1925, 12, p. 309-321
- Feibleman, James K., "Theory of integrative levels", British journal for the philosophy of science, 5: 1954, 17, p. 59-66
- Foskett, Douglas John, "The theory of integrative levels and its relevance to the design of information systems", Aslib proceedings, 30: 1978, 6, p. 202-208
- Greenberg, Gary and Tobach, Ethel, "Behavioral Evolution and Integrative Levels", Lawrence Earlbaum Associates, Inc. Publisher, 1984
- Korzybski, Alfred, Science and Sanity: An Introduction to Non-Aristotelian Systems and General Semantics, 1933
- Hartmann, N., Die Aufbau der realen Welt: Grundriss der allgemeinen Kategorienlehre, De Gruyter, 1940
- Hartmann, N., New ways of ontology, Greenwood Press, 1952
- Morgan, C.L., Emergent evolution, Williams and Norgate, London 1923
- Needham, Joseph, "Integrative levels: a revaluation of the idea of progress", in Time: the refreshing river: essays and addresses, 1932-1942, Allen and Unwin, London 1943, p. 233-272
- Novikoff, A.B., "The concept of integrative levels and biology", Science, 101: 1945, p. 209-215
- Pettersson, M., Complexity and evolution, Cambridge University Press, 1996
- Poli, R., "Levels", Axiomathes, 9: 1998, 1-2. p. 197-211
- Poli, R., "The basic problem of the theory of levels of reality", Axiomathes, 12: 2001, 3-4, p. 261-283