International Encyclopedia of Systems and Cybernetics

"A descriptive and investigative strategy which gives account of phenomena in terms of a series of isolated parts, coupled together by direct causal linkages" (T.F.H. ALLEN & T.B. STARR,.1, p.276).

2a. A principle "according (to which) all scientific concepts are reducible to a set of ultimately irreducible concepts" (R.L. ACKOFF, 1974, p.53).

2b. "The belief that everything in the world and every experience of it can be reduced, decomposed, or dissembled to ultimatly simple elements, indivisible parts" (R.L. ACKOFF, 1991, p.325).

3. The claim "that properties of a whole are explicable in terms of properties of the constituent elements" (G. KLIR, 1991, p.24).

4. "… the task to find the simplest, most economical and (usually) most elegant explanation that will cover the known data" (G. BATESON, 1979, p.230).

T.F.H. ALLEN and T.B. STARR add: "Ambiguity in relationship between parts is met with further subdivision until the ambiguity disappears" (Ibid).

As a result "Reductionism is thus the strongest possible way of ordering the list of the various sciences" (I.I. MITROFF and H.A. LINSTONE 1993, p.165).

Commenting his definition, ACKOFF states that these "ultimate concepts", according to some "were provided by direct observation" and to others "thought of as undefined concepts of a formal system ". And, "Whatever their source, these concepts were identified as "physical thing predicates"; that is, physical properties of things".

BATESON adds to his definition the following caveat: "Beyond this, reductionism becomes a vice if it is accompanied by an overly strong insistence that the simplest explanation is the only explanation. The data may have to be understood within some larger gestalt" (Ibid).

For a good example, see: Selection (Multilevel)

Reductionism is a paradigm. R. ROSEN expresses this as follows: "The belief that any natural system can be so decomposed (note: i.e. extensively, and possibly limitlessly), and that the laws governing the motions of these particles can be determined, is the essence of reductionism" (1979, p.174). The "belief" is something like the hardening of an assumption.

The conceptual origins of reductionism are to be found in DESCARTES and NEWTON, if we are not going back in time to DEMOCRITUS, EPICURUS and LUCRETIUS.

The basic (and largely unconscious) tenets of reductionism seem to be the following:

- what should be researched are the properties of objects, which are "real" and perfectly knowledgeable

- the observer or experimenter is "transparent", i.e., without influence on the perceived objects

- the "et ceteris paribus" postulate can be applied without restrictions, which allows for linear causal explanations

- supposedly, no significant aspects of phenomena are thus left out, (forgetting for example interrelations between elements or parts, or between levels)

- larger contexts do not influence upon phenomena

Systems concepts are however not opposed to the reductionist approach, as they admit levels of description. This point was made as follows by P. WEISS (quoted by G. KLIR, 1991, p.26), who describes a neutral stand: "The reductionist likes to move from the top down, gaining precision of information about fragments as he descends, but losing information content about the larger orders he leaves behind: The other proceeds in the opposite direction, from below, trying to retrieve the lost information content by reconstruction, but recognizes that that information is not forthcoming unless he already had it on record in the first place. The difference between the two processes, (is) determined partly by personal predilection, but largely also by historical tradition".

This does not makes clear that the main concern of the systemist are the interactions within the same level as well as between different levels of complexity, in the whole.

Moreover, as stated by I. PRIGOGINE (quoted by F. David PEAT, 1987, p.64), "… there is no "fundamental level" in nature but rather each level involves its unique description and is conditioned by the levels around it".

In some sense, reductionism is thus "inscribed" within the systemic approach as: "Nature… requires pluralistic descriptions and … this pluralism must contain both causal and synchronistic aspects" (Ibid).

In an overview of this subject, J.A. GOGUEN and F.J. VARELA conclude: "Reductionism implies attention to a lower level, while holism implies attention to a higher level. They are intertwined in any satisfactory description; and each entails some loss relative to our cognitive preferences, as well as some gain" (1979, p.42).

Reductionism may also be understood as the use of OCKAM's razor, as stated by P. CHECKLAND, who writes: "And we use reductionism in another sense in explanation, explaining the results using the smallest number possible number of concepts, only importing more elaborate concepts when defeated in this" (1976, p.128).

Still another meaning frequently given to reductionism is the stand according to which social and biological sciences can ultimately be reduced to explanations based on physical sciences. While anything social or biological is by necessity based on physical properties, the reductionist stand ignores the existence of succesive levels of complexity grounded on the emergence of dissipative structures and synergies.

On this topic D. CAMPBELL accepts: "… the limited emergentist principle that laws of biology, psychology and sociology exist which are not described by the laws of physics and inorganic chemistry. These emergent laws are compatible with the laws of physics and chemistry but not derivable from them" (1975, p.1104).

At long last, the fundamental difficulty becomes obvious: so-called laws must be noncontradictory between them to be acceptable on all levels. The best example has been the elimination of the vitalist stand in biology when the appearent impossibility of life in terms of classical thermodynamics was taken care of succesively by such models as open system, homeostasis and finally dissipative structuration. It should be noted that none of these models are "laws", no their applications limited to any particular scientific discipline.

P.M. ALLEN et al. observe that "the very success of reductionist science has… provided man with the power to radically change his environment. However, this science has afforded almost no knowledge of the probable effects of such actions in the complex systems encountered in the domains of biology, ecology and socio-economics. Policy today must be formulated in a world of ever increasing interaction and complexity" (1984, p.2).