Integrative Levels Classification project scheme monograph references

« Emergence and the nature of levels

Layers and strata

Hartmann makes a strong distinction between four major strata, or planes, of reality (the material, the organic, the mental, and the spiritual), and minor layers within them, of which the typical example are those within the material stratum (atoms, molecules, bodies, etc.) and within the organic stratum (cells, organisms, populations, etc.). While layers are in a relation of over-forming (Überformung) between them, meaning that each one is made with elements of the lower one, strata are in a relation of building-above (Überbauung), meaning that lower strata are a previous condition for the existence of higher ones, but not as their material constituents. Organisms are required for minds to exist, yet minds are not made of organisms [Har40-42; Pol98-01].

Which is, then, the nature of the building-above relationship? This is maybe the most mysterious aspect of emergence. The body-mind relationship, corresponding to the boundary between the organic stratum and the mental stratum, is often cited as a case of strong emergence — when it is not the basis for fully dualistic philosophies; Nicolescu looks for a solution by postulating a quantistic stratum, shared by both subatomic particles and minds [Nic88-06; Pol08b].

A promising clue for understanding the building-above relationship can be found in a passage by biologist François Jacob, observing that all major transitions in evolution correspond to the establishment of some mechanism of memory [Jac70]. Indeed, the cultural stratum emerges where humans trade the memory of their knowledge through cultural transmission [eg Cav96]; the mental stratum emerges where the external situation is represented in the consciousness of an individual as percepts and concepts; and even in the organic stratum, the anatomy, physiology, and behaviour of organisms can be seen as a forms of knowledge about their environment, to which they are adapted. Lorenz illustrates this with the examples of the hydrodynamic shape of fishes, viewed as knowledge about the mechanic properties of water in which they have to live; and of the structure of horse hooves, viewed as reflecting the shape of the steppe in which they have to live [Lor73-81]. Thus, building-above can be seen as a representation of patterns of a lower stratum into a new kind of medium.

In a phylogenetic view, each stratum undergoes a different kind of evolution producing its own diverse forms: material, living, individual, social, cultural. "Organization" at a new stratum takes place when forms ("phenotype") are produced indirectly by some separate replicators ("genotype" [Bou]) where information about the environment can be stored and accumulate. Replicators can occur in different varieties, which are selected by the pressure of external factors, so that in time they develop patterns modelling the external environment more accurately.

Genes, brains, socially shared ideas (memes or inscriptions), and recorded documents are well-known memory devices [Daw89; Fer07; Hul88]. Ideas can also be shared in animal societies, like the ability to wash sweet potatoes having spread in a community of Japanese macaques; however, in human societies their transmission is much more efficient thanks to the appearance of language, that acts as another major replicator of patterns; similarly, the invention of writing systems and other technological devices opens the road for the further cultural stratum of artifacts and "mentefacts" [Kyl5_] transcending the actual presence of people who had generated them. It is less clear what replicators can be in the material stratum, although Prigogine remarks how the traditionally static view of physics can be replaced with one in which new structures progressively appear at a series of bifurcation points [Pri80].

More evolved memories allows systems for different performances. Material systems react to external perturbations in a mechanic way, by simply changing their own structure. Organic systems, thanks to their genetic memory, are able to react in more sophisticated ways, thus tending to keep their internal state unaltered (homeostasis). Cultural systems, thanks to their social memory, are even able to change their external environment according to their own purposes [Fle96; Hof09-12]. A further kind of memory can be identified, that stored by humans into external artifacts, like machines, robots, books, or the Semantic Web, which are able to promote changes in the environment in absence of their original creators.

We can thus envisage a framework of the evolution of different forms of organization:


These observations support a view of reality as structured into at least five strata, each one representing patterns of the previous one in networks of a novel nature:

These five strata correspond more or less to the four ones of Hartmann with the further division of his spiritual stratum into a social one (Hartmann's "objective spirit") and a cultural one (Hartmann's "objectivated spirit"). We have developed the list also with the initial addition of form, consisting of abstract logical and mathematical structures; these are described by Hartmann as rather falling in a realm of "ideal being", separated from that of "real being" which includes all the other strata. Indeed, the collocation of logical and mathematical structures is a critical question in any model of the world: many see them only as constructions of the human spirit, hence laying in the mental stratum (like in Kant) or even in the social stratum. An ontological approach, instead, can suppose a prior existence of forms independent from the human notion of them: this model was adopted eg by Walter Marvin, who listed the logical-mathematical, physical, biological, mental, human and social strata [Mar1912]. Feibleman also listed three "theoretical" levels, ontological, logical, and mathematical, preceding the "empirical" ones [Fei51]. The reappearance of forms in the higher strata of mind and culture could be explained by an evolutionary epistemology: the notions of number, of logical operations, etc. can have evolved in human minds because they are careful representations of the structure of reality, which makes them working in everyday life, hence useful for the fitness of the organism. Higher strata can then be viewed as representations of abstract forms, in the sense that they make them real in concrete objects and processes. This is acknowledged intuitively in many KOSs, including Roget's Thesaurus and Dahlberg's Information Coding Classification, by placing the concepts of logic and mathematics at the beginning of the schedules; ILC will do the same.

Other debated issues about strata concern the status of the organic stratum: some, like Popper [Pop72-94] and Poli [Pol98-06], see it as just a part of the material one; and the identity of the highest strata, often described as "social" rather than "spiritual" since Roy Sellars [Sel26-59], and seen by Poli as tangled with the mental one rather than just laying above it [Pol06b; Pol]. Alexander even claimed that the highest level is that of an impersonal "deity" [Ale20-21].

Our list of the strata can be compared with the terminology of philosophers dealing with levels:

 Lloyd MorganRW SellarsHartmannPoliPopper
form ideal being 
mattermatterinanimatematerialmaterialworld 1
mindmindmindpsychicpsychologicalworld 2
societypersonal spirit
objective spirit
objectivated spirit
world 3

The material and living strata can be decomposed quite easily into their layers: eg for Lloyd Morgan matter can be either physical or chemical, while mind can be conscious or reflective; for Hartmann, the spiritual stratum includes personal, objective (social), and objectivated (cultural) spirit. Modern science often acknowledges matter as including subatomic particles, atoms, molecules, celestial objects; and life as including cells, organisms, and biological populations. Layers within higher strata are less immediately identified, but levelled structures are often cited, eg families, clans, cities, nations, and the global community can be listed in the social stratum.

A principle for knowledge organization »

References cited in this section

Bou: Economic development as an evolutionary system / Kenneth E Boulding – University of Colorado : <> : 200_?

Cav96: Geni, popoli e lingue. Capitolo 6: Trasmissione ed evoluzione culturali / Luigi Luca Cavalli-Sforza – Adelphi : Milano : 1996 « Gènes, peuples et langues

Daw89: The selfish gene # 2 / Richard Dawkins – Oxford university press : 1989

Fer07: Documentalità: ontologia del mondo sociale / Maurizio Ferraris = Ethics & politics. 9: 2007. 2. P 240-329

Hul88: Science as a process : an evolutionary account of the social and conceptual development of science / David Hull – University of Chicago press : 1988

Pri80: From being to becoming : time and complexity in the physical sciences / Ilya Prigogine – Freeman : 1980


Integrative Levels Classification. Philosophy. Integrative levels. Layers and strata / Claudio Gnoli – ISKO Italy : <> : 2009.02.12 - 2012.07.26 -

  Integrative Levels Classification project scheme monograph references