Descartes held that non-human animals could be reductively explained as automata De homine, 1662.

Reductionism refers to several related but distinct philosophical positions regarding the connections between phenomena, or theories, "reducing" one to another, usually considered "simpler" or more "basic".[1] The Oxford Companion to Philosophy suggests that it is "one of the most used and abused terms in the philosophical lexicon" and suggests a three part division:[2]

  3. Theory reductionism: the suggestion that a newer theory does not replace or absorb the old, but reduces it to more basic terms. Theory reduction itself is divisible into three: translation, derivation and explanation.[3]

Reductionism can be applied to objects, phenomena, explanations, theories, and meanings.[3][4][5]

In the sciences, application of methodological reductionism attempts explanation of entire systems in terms of their individual, constituent parts and their interactions. For example, the heat of a gas is reduced to nothing but the average kinetic energy of its molecules in motion. Thomas Nagel speaks of psychophysical reductionism (the attempted reduction of psychological phenomena to physics and chemistry), as do others and physico-chemical reductionism (the attempted reduction of biology to physics and chemistry), again as do others.[6] In a very simplified and sometimes contested form, such reductionism is said to imply that a system is nothing but the sum of its parts.[4][7] However, a more nuanced view is that a system is composed entirely of its parts, but the system will have features that none of the parts have.[8] "The point of mechanistic explanations is usually showing how the higher level features arise from the parts."[7]

Other definitions are used by other authors. For example, what Polkinghorne calls conceptual or epistemological reductionism[4] is the definition provided by Blackburn[9] and by Kim:[10] that form of reductionism concerning a program of replacing the facts or entities entering statements claimed to be true in one area of discourse with other facts or entities from another area, thereby providing a relationship between them. Such a connection is provided where the same idea can be expressed by "levels" of explanation, with higher levels reducible if need be to lower levels. This use of levels of understanding in part expresses our human limitations in grasping a lot of detail. However, "most philosophers would insist that our role in conceptualizing reality [our need for an hierarchy of "levels" of understanding] does not change the fact that different levels of organization in reality do have different properties."[8]


Reductionism should be distinguished from eliminationism: reductionists do not deny the existence of phenomena, but explain them in terms of another reality; eliminationists deny the existence of the phenomena themselves. For example, eliminationists deny the existence of life by their explanation in terms of physical and chemical processes. Daniel Dennett denies the existence of consciousness.[11]



Most philosophers delineate three types of reductionism and antireductionism.[2]

Ontological reductionism





Ontological reductionism takes two different forms: token ontological reductionism and type ontological reductionism. Token ontological reductionism is the idea that every item that exists is a sum item. For perceivable items, it says that every perceivable item is a sum of items at a smaller level of complexity. Token ontological reduction of biological things to chemical things is generally accepted.

Type ontological reductionism is the idea that every type of item is a sum type of item, and that every perceivable type of item is a sum of types of items at a lower level of complexity. Type ontological reduction of biological things to chemical things is often rejected.[16]


Methodological reductionism


Methodological reductionism, therefore, is the position that all scientific theories either can or should be reduced to a single super~theory through the process of theoretical reduction.

Theory reductionism

Theory reduction is the process by which one theory absorbs another. For example, both Kepler's laws of the motion of the planets and Galileo's theories of motion worked out for terrestrial objects are reducible to Newtonian theories of mechanics because all the explanatory power of the former are contained within the latter. Furthermore, the reduction is considered to be beneficial because Newtonian mechanics is a more general theory—that is, it explains more events than Galileo's or Kepler's. Theoretical reduction, therefore, is the reduction of one explanation or theory to another—that is, it is the absorption of one of our ideas about a particular thing into another idea.

In science



Some strong reductionists believe that the behavioral sciences should become "genuine" scientific disciplines based on genetic biology, and on the systematic study of culture (see Richard Dawkins's concept of memes). In his book The Blind Watchmaker, Dawkins introduced the term "hierarchical reductionism"[18] to describe the view that complex systems can be described with a hierarchy of organizations, each of which is only described in terms of objects one level down in the hierarchy. He provides the example of a computer, which under hierarchical reductionism is explained in terms of the operation of hard drives, processors, and memory, but not on the level of AND OR gates, or on the even lower level of electrons in a semiconductor medium.


The idea that phenomena such as emergence and work within the field of complex systems theory pose limits to reductionism has been advocated by Stuart Kauffman.[21] Emergence is strongly related to nonlinearity.[22] The limits of the application of reductionism are claimed to be especially evident at levels of organization with higher amounts of complexity, including living cells,[23] neural networks, ecosystems, society, and other systems formed from assemblies of large numbers of diverse components linked by multiple feedback loops.[23][24]

Nobel laureate P.W. Anderson used the idea that symmetry breaking is an example of an emergent phenomenon in his 1972 Science paper "More is different" to make an argument about the limitations of reductionism.[25] One observation he made was that the sciences can be arranged roughly in a linear hierarchy particle physics, many body physics, chemistry, molecular biology, cellular biology, physiology, psychology, social sciences — in that the elementary entities of one science obeys the laws of the science that precedes it in the hierarchy; yet this does not imply that one science is just an applied version of the science that precedes it. He writes that "At each stage, entirely new laws, concepts and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one. Psychology is not applied biology nor is biology applied chemistry."

Disciplines such as cybernetics and systems theory embrace a non-reductionist view of science, sometimes going as far as explaining phenomena at a given level of hierarchy in terms of phenomena at a higher level, in a sense, the opposite of a reductionist approach.[26]

In mathematics

In mathematics, reductionism can be interpreted as the philosophy that all mathematics can (or ought to) be built on a common foundation, which is usually axiomatic set theory. Ernst Zermelo was one of the major advocates of such a view; he also developed much of axiomatic set theory. It has been argued that the generally accepted method of justifying mathematical axioms by their usefulness in common practice can potentially undermine Zermelo's reductionist program.[27]


The incompleteness theorems of Kurt Gödel, published in 1931, raised doubts about the attainability of an axiomatic foundation for all of mathematics. Any such foundation would have to include axioms powerful enough to describe the arithmetic of the natural numbers (a subset of all mathematics). Yet Gödel proved that for any self-consistent recursive axiomatic system powerful enough to describe the arithmetic of the natural numbers, there are propositions about the natural numbers that cannot be proved from the axioms, but which we can prove in the natural language with which we described the axioms. (Such propositions are known as formally undecidable propositions.)

In religion


In linguistics

Linguistic reductionism is the idea that everything can be described or explained in a language with a limited number of core concepts, and combinations of those concepts.[33] A key example is the language Toki Pona.

In philosophy


Free will

Main article: Free will



Main article: Antireductionism

The antireductionist takes this position as a minimum requirement upon the reductionist: "What is unclear is how the pre-theoretical intuitions [for example, of free will] are to be accommodated theoretically within favored analyses... At the very least the anti-reductionist is owed an account of why the intuitions arise if they are not accurate."[38]

A contrast to the reductionist approach is holism or emergentism. Holism is the idea that things can have properties, (emergent properties), as a whole that are not explainable from the sum of their parts. The principle of holism was concisely summarized by Aristotle in the Metaphysics: "The whole is more than the sum of its parts".

The term greedy reductionism, coined by Daniel Dennett, is used to criticize inappropriate use of reductionism.




Alfred North Whitehead set his metaphysical thinking in opposition to reductionism. He refers to this as the "fallacy of the misplaced concreteness". His scheme set out to frame a rational, general understanding of things, that was derived from our reality.



Fragmentalism is an alternative term for ontological reductionism,[41] although fragmentalism is frequently used in a pejorative sense.[42] Anti-realists use the term fragmentalism in arguments that the world does not exist of separable entities, instead consisting of wholes. For example, advocates of this position hold that:




These perspectives are not new and in the early twentieth century, William James noted that rationalist science emphasized what he termed fragmentation and disconnection.[45]

Such views also underpin many criticisms of the scientific method:

The scientific method only acknowledges monophasic consciousness. The method is a specialized system that focuses on studying small and distinctive parts in isolation, which results in fragmented knowledge.[45]

An alternative usage of this term is in cognitive psychology. Here, George Kelly developed "constructive alternativism" as a form of personal construct psychology, this provided an alternative to what he saw as "accumulative fragmentalism". In this theory, knowledge is seen as the construction of successful mental models of the exterior world, rather than the accumulation of independent "nuggets of truth".[46]

See also


  3. 1 2 Alyssa Ney. "Reductionism". Internet Encyclopedia of Philosophy. IEP, University of Tennessee. Retrieved March 13, 2015.
  4. 1 2 3 John Polkinghorne (2002). "Reductionism". Interdisciplinary Encyclopedia of Religion and Science. Advanced School for Interdisciplinary Research; Pontifical University of the Holy Cross.
  7. 1 2 Peter Godfrey-Smith (2013). Philosophy of Biology. Princeton University Press. p. 16. ISBN 9781400850440.
  9. Simon Blackburn. "Entry on 'reductionism'". Oxford Dictionary of Philosophy. p. 311.. Richard Jones distinguishes the two, arguing that many ontological and epistemological reductionists affirm the need for different levels of concepts for different degree of complexity while affirming a reduction of theories. Richard H. Jones (2000), Reductionism: Analysis and the Fuullness of Reality, pp. 27-28, 32. Lewisburg, Pa.: Bucknell University Press
  11. Daniel C. Dennett, Consciousness Explained. Boston: Back Bay Books, 1992.
  12. Axelrod and Cohen "Harnessing Complexity"
  16. "Reductionism - By Branch / Doctrine - The Basics of Philosophy".
  18. Interview with Third Way magazine in which Richard Dawkins discusses reductionism and religion, February 28, 1995
  21. Beyond Reductionism: Reinventing the Sacred by Stuart Kauffman
  26. "Downward Causation".
  31. "".
  33. Mastin 2008,
  35. Juarrero,, A. "Causality as Constraint". Archived from [  the original] on June 12, 2011.
  36. Paul Guyer, "18th Century German Aesthetics," Stanford Encyclopedia of Philosophy
  43. Anatoly P. Liferov, Global Education as a Trend Reflecting the Problems of Today and Meeting the Requirements of Tomorrow
  44. Yunkaporta on Kakkib and Oneness, Tyson Yunkaporta, Friday, January 05, 2007
  45. 1 2 Tara W. Lumpkin, Perceptual Diversity: Is Polyphasic Consciousness Necessary for Global Survival? December 28, 2006,
  46. Pope ML & Watts M (1988). "Constructivist Goggles: Implications for Process in Teaching and Learning Physics". Eur. J. Physics. 9 (2): 101–109. Bibcode:1988EJPh....9..101P. doi:10.1088/0143-0807/9/2/004.

Further reading

External links

Look up reductionism in Wiktionary, the free dictionary.