© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Complexity

Complementarity in biological systems: A complexity view

Neil David Theise, Menas C. Kafatos

Published Jul 1, 2013• 63 citations

Abstract

Niels Bohr and Max Delbruck believed that complementarity—such as wave–particle duality—was not limited to the quantum realm, but had correlates in the study of living things. Biological complementarity would indicate that no single technique or perspective allows comprehensive viewing of all of a biological entity's complete qualities and behaviors; instead, complementary perspectives, necessarily and irrevocably excluding all others at the moment an experimental approach is selected, would be necessary to understand the whole. Systems biology and complexity theory reveal that, as in the quantum realm, experimental observations themselves limit our capacity to understand a biological system completely because of scale‐dependent “horizons of knowledge,” a form of biological complementarity as predicted by Bohr and Delbruck. Specifically, observational selection is inherently, irreducibly coupled to observed biological systems as in the quantum realm. These nested systems, beginning with biomolecules in aqueous solution all the way up to the global ecosystem itself, are understood as a seamless whole operating simultaneously and complementarily at various levels. This selection of an observational stance is inseparable from descriptions of biology indicates—in accordance with views of thinkers such as von Neumann, Wigner, and Stapp—that even at levels of scale governed by classical physics, at biological scales, observational choice remains inextricably woven into the establishment, in the observational moment, of the present conditions of existence. These conceptual shifts will not only have theoretical impact, but may point the way to new, successful therapeutic interventions, medically (at the scale of organisms) or environmentally/economically (at a global scale). © 2013 Wiley Periodicals, Inc. Complexity 18: 11‐20, 2013

DOI: 10.1002/cplx.21453

Related papers

Complementarity & Reality

Ted Dace

Niels Bohr developed the framework of complementarity in response to the binding of measuring device and quantum system into an irreducible whole or "individual" at the instant of measurement. On the grounds that an organism and its environment are also bound irreducibly upon interaction, Bohr extended complementarity to biology and psychology, treating mechanistic reduction of the organism and neural objectification of consciousness as mere perspectives opposed by equally valid perspectives. In contrast to Bohr's aversion to metaphysical speculation, Heisenberg suggested that the quantum-mechanical wave function represents a real entity which determines probable outcomes of measurements given the forces acting on the system. In light of Bohr's parallel between quantum and biological systems, the probability wave of the atom ought to be mirrored in the equally intangible consciousness of the organism. I propose further that life is indeed an irreducible property of the organism and that mechanistic biology mischaracterizes life. Key to my analysis is the dual nature of time.

Journal of consciousness exploration & research•Jun 24, 2025•0 citations

Entanglement limits duality and vice versa

Xiao‐Feng Qian, A. Nick Vamivakas, Joseph H. Eberly

Ninety years ago in 1927, at an international congress in Como, Italy, Niels Bohr gave an address which is recognized as the first instance in which the term "complementarity", as a physical concept, was spoken publicly [1], revealing Bohr's own thinking about Louis de Broglie's "duality". Bohr had very slowly accepted duality as a principle of physics: close observation of any quantum object will reveal either wave-like or particle-like behavior, one or the other of two fundamental and complementary features. Little disagreement exists today about complementarity's importance and broad applicability in quantum science. Book-length scholarly examinations even provide speculations about the relevance of complementarity in fields as different from physics as biology, psychology and social anthropology, connections which were apparently of interest to Bohr himself (see Jammer [2], Murdoch [3] and Whitaker [4]). Confusion evident in Como following his talk was not eliminated by Bohr's article [1], and complementarity has been subjected to nine decades of repeated examination ever since with no agreed resolution. Semi-popular treatments [5] as well as expert examinations [6-9] show that the topic cannot be avoided, and complementarity retains its central place in the interpretation of quantum mechanics. However, recent approaches by our group [10-13] and others [14-20] to the underlying notion of coherence now allow us to present a universal formulation of complementarity that may signal the end to the confusion. We demonstrate a new relationship that constrains the behavior of an electromagnetic field (quantum or classical) in the fundamental context of two-slit experiments. We show that entanglement is the ingredient needed to complete Bohr's formulation of complementarity, debated for decades because of its incompleteness.

arXiv:1803.04611•Optica•Jul 30, 2018•91 citations

Conclusion

John P. Losee

The analogical extensions of Niels Bohr's principle of complementarity to the disciplines of biology, psychology, and theology are ineffective. It has been argued, moreover, that the principle of complementarity is ineffective within quantum theory itself. Bohr supported the claim that complementary pictorial-level interpretations are necessary for the explanation of quantum phenomena by invoking a correspondence argument. Henry Margenau criticized Bohr for recommending that physicists accept an irreconcilable dilemma, the horns of which are complementary "descriptions" in terms of classical observables and causal accounts in terms of abstract states. In his various publications, Margenau created a number of diagrams to represent the confirmation process. He agreed with P. W. Bridgman that operational definitions provide important links between constructs and the results of instrumental procedures. Despite Margenau's protest, many scientists in the 1930s were receptive to the idea that pictures of classical particles and waves are needed to complete the interpretation of quantum phenomena.

Routledge eBooks•Jul 28, 2017•0 citations

Complementarity in Biology

John P. Losee

Bohr recommended complementarity as a criterion of completeness for explanations of quantum phenomena. To explain fully the single-slit diffraction of electrons, for instance, one must append two mutually exclusive pictures of the behavior of the electrons between the diaphragm and photographic plate. The two pictures are not applied arbitrarily. Spatiotemporal description is appropriate given a rigidly mounted diaphragm. Causal interaction—via energy/momentum transfer—is appropriate given a movable diaphragm. The biologist who studies an animal's behavior in a particular ecosystem cannot perform the dissections and chemical analyses to uncover the underlying physiological changes within the animal without compromising the original study. Bohr maintained that every experimental arrangement with which one could study the behavior of the atoms constituting an organism will exclude the possibility of maintaining the organism alive. Self-preservation and self-generation are processes fundamental to living organisms. Bohr maintained that the "notion of life" is an "element for which an explanation is neither possible nor required".

Routledge eBooks•Jul 28, 2017•1 citation

Non-linearity, complexity, and quantization concepts in biology

Neil David Theise, Jack A. Tuszyński

Founders of quantum mechanics (QM) anticipated that revisions to classical physics due to strange elements of quantum reality, would necessitate similar changes in biology. Complexity theory, systems biology and quantum biology provide possible solutions indicating that subject/object separation is a useful fiction for reductive science. Direct correlates to such QM observational/measurement issues as Complementarity and Uncertainty may justify the introduction of an analog of Heisenberg's uncertainty and the Planck constant for living systems. The phase space of "adjacent possibles" for biological systems from which one "actual" is selected resembles the collapse of the QM wave function. Since biological systems are hierarchical, this occurs across organizational scales resulting in biological coherence. The location of a quantum/classical boundary is unclear due to complexity. Whether biological systems' characteristics arise directly from QM or are of a different origin remains unsettled. To combine non-linear with quantum properties across biological scales we propose the Method of Coherent Structures (MCS), developed for quantum many-body systems. In MCS, a higher-level scale provides a classical envelope for quantum fluctuations at the lower scale. It yields a seamless transition from non-linear classical fields to quantum excitations and accounts for the emergence of complexity by incorporating metabolic energy supply.

Frontiers in Human Neuroscience•Jan 7, 2026•1 citation

Complementarity in Psychology

John P. Losee

Niels Bohr accepted the distinction stressed by Immanuel Kant and others between the awareness of an object and the awareness of being aware of that object. He noted that one of the "epistemological implications" of the success of quantum theory is the necessity of directing attention to the "placing of the subject-object distinction". Causal pictures and vitalistic pictures, like particle pictures and wave pictures in quantum theory, are interpretations that supplement each other. These pictures are complementary in the sense that both types of picture are required for completeness. This is the case both in quantum physics and psychology. The mutual exclusivity of interpretations is a cornerstone of the principle of complementarity, as it is applied within quantum theory. Bohr's analogical extension of the principle of complementarity to psychology is unconvincing. A more appropriate analogy to causal and vitalistic interpretations in psychology would be from fluid and particulate models of the behavior of aqueous solutions.

Routledge eBooks•Jul 28, 2017•0 citations

Niels Bohr and Max Delbruck believed that complementarity—such as wave–particle duality—was not limited to the quantum realm, but had correlates in the study of living things. Biological complementarity would indicate that no single technique or perspective allows comprehensive viewing of all of a biological entity's complete qualities and behaviors; instead, complementary perspectives, necessarily and irrevocably excluding all others at the moment an experimental approach is selected, would be necessary to understand the whole. Systems biology and complexity theory reveal that, as in the quantum realm, experimental observations themselves limit our capacity to understand a biological system completely because of scale‐dependent “horizons of knowledge,” a form of biological complementarity as predicted by Bohr and Delbruck. Specifically, observational selection is inherently, irreducibly coupled to observed biological systems as in the quantum realm. These nested systems, beginning with biomolecules in aqueous solution all the way up to the global ecosystem itself, are understood as a seamless whole operating simultaneously and complementarily at various levels. This selection of an observational stance is inseparable from descriptions of biology indicates—in accordance with views of thinkers such as von Neumann, Wigner, and Stapp—that even at levels of scale governed by classical physics, at biological scales, observational choice remains inextricably woven into the establishment, in the observational moment, of the present conditions of existence. These conceptual shifts will not only have theoretical impact, but may point the way to new, successful therapeutic interventions, medically (at the scale of organisms) or environmentally/economically (at a global scale). © 2013 Wiley Periodicals, Inc. Complexity 18: 11‐20, 2013

Niels Bohr developed the framework of complementarity in response to the binding of measuring device and quantum system into an irreducible whole or "individual" at the instant of measurement. On the grounds that an organism and its environment are also bound irreducibly upon interaction, Bohr extended complementarity to biology and psychology, treating mechanistic reduction of the organism and neural objectification of consciousness as mere perspectives opposed by equally valid perspectives. In contrast to Bohr's aversion to metaphysical speculation, Heisenberg suggested that the quantum-mechanical wave function represents a real entity which determines probable outcomes of measurements given the forces acting on the system. In light of Bohr's parallel between quantum and biological systems, the probability wave of the atom ought to be mirrored in the equally intangible consciousness of the organism. I propose further that life is indeed an irreducible property of the organism and that mechanistic biology mischaracterizes life. Key to my analysis is the dual nature of time.

Ninety years ago in 1927, at an international congress in Como, Italy, Niels Bohr gave an address which is recognized as the first instance in which the term "complementarity", as a physical concept, was spoken publicly [1], revealing Bohr's own thinking about Louis de Broglie's "duality". Bohr had very slowly accepted duality as a principle of physics: close observation of any quantum object will reveal either wave-like or particle-like behavior, one or the other of two fundamental and complementary features. Little disagreement exists today about complementarity's importance and broad applicability in quantum science. Book-length scholarly examinations even provide speculations about the relevance of complementarity in fields as different from physics as biology, psychology and social anthropology, connections which were apparently of interest to Bohr himself (see Jammer [2], Murdoch [3] and Whitaker [4]). Confusion evident in Como following his talk was not eliminated by Bohr's article [1], and complementarity has been subjected to nine decades of repeated examination ever since with no agreed resolution. Semi-popular treatments [5] as well as expert examinations [6-9] show that the topic cannot be avoided, and complementarity retains its central place in the interpretation of quantum mechanics. However, recent approaches by our group [10-13] and others [14-20] to the underlying notion of coherence now allow us to present a universal formulation of complementarity that may signal the end to the confusion. We demonstrate a new relationship that constrains the behavior of an electromagnetic field (quantum or classical) in the fundamental context of two-slit experiments. We show that entanglement is the ingredient needed to complete Bohr's formulation of complementarity, debated for decades because of its incompleteness.

The analogical extensions of Niels Bohr's principle of complementarity to the disciplines of biology, psychology, and theology are ineffective. It has been argued, moreover, that the principle of complementarity is ineffective within quantum theory itself. Bohr supported the claim that complementary pictorial-level interpretations are necessary for the explanation of quantum phenomena by invoking a correspondence argument. Henry Margenau criticized Bohr for recommending that physicists accept an irreconcilable dilemma, the horns of which are complementary "descriptions" in terms of classical observables and causal accounts in terms of abstract states. In his various publications, Margenau created a number of diagrams to represent the confirmation process. He agreed with P. W. Bridgman that operational definitions provide important links between constructs and the results of instrumental procedures. Despite Margenau's protest, many scientists in the 1930s were receptive to the idea that pictures of classical particles and waves are needed to complete the interpretation of quantum phenomena.

Bohr recommended complementarity as a criterion of completeness for explanations of quantum phenomena. To explain fully the single-slit diffraction of electrons, for instance, one must append two mutually exclusive pictures of the behavior of the electrons between the diaphragm and photographic plate. The two pictures are not applied arbitrarily. Spatiotemporal description is appropriate given a rigidly mounted diaphragm. Causal interaction—via energy/momentum transfer—is appropriate given a movable diaphragm. The biologist who studies an animal's behavior in a particular ecosystem cannot perform the dissections and chemical analyses to uncover the underlying physiological changes within the animal without compromising the original study. Bohr maintained that every experimental arrangement with which one could study the behavior of the atoms constituting an organism will exclude the possibility of maintaining the organism alive. Self-preservation and self-generation are processes fundamental to living organisms. Bohr maintained that the "notion of life" is an "element for which an explanation is neither possible nor required".

Founders of quantum mechanics (QM) anticipated that revisions to classical physics due to strange elements of quantum reality, would necessitate similar changes in biology. Complexity theory, systems biology and quantum biology provide possible solutions indicating that subject/object separation is a useful fiction for reductive science. Direct correlates to such QM observational/measurement issues as Complementarity and Uncertainty may justify the introduction of an analog of Heisenberg's uncertainty and the Planck constant for living systems. The phase space of "adjacent possibles" for biological systems from which one "actual" is selected resembles the collapse of the QM wave function. Since biological systems are hierarchical, this occurs across organizational scales resulting in biological coherence. The location of a quantum/classical boundary is unclear due to complexity. Whether biological systems' characteristics arise directly from QM or are of a different origin remains unsettled. To combine non-linear with quantum properties across biological scales we propose the Method of Coherent Structures (MCS), developed for quantum many-body systems. In MCS, a higher-level scale provides a classical envelope for quantum fluctuations at the lower scale. It yields a seamless transition from non-linear classical fields to quantum excitations and accounts for the emergence of complexity by incorporating metabolic energy supply.

Niels Bohr accepted the distinction stressed by Immanuel Kant and others between the awareness of an object and the awareness of being aware of that object. He noted that one of the "epistemological implications" of the success of quantum theory is the necessity of directing attention to the "placing of the subject-object distinction". Causal pictures and vitalistic pictures, like particle pictures and wave pictures in quantum theory, are interpretations that supplement each other. These pictures are complementary in the sense that both types of picture are required for completeness. This is the case both in quantum physics and psychology. The mutual exclusivity of interpretations is a cornerstone of the principle of complementarity, as it is applied within quantum theory. Bohr's analogical extension of the principle of complementarity to psychology is unconvincing. A more appropriate analogy to causal and vitalistic interpretations in psychology would be from fluid and particulate models of the behavior of aqueous solutions.