Reductionism and holism It was a fad in certain circles in the 1990s to announce that “reductionism is dead,” and that holism is necessary in order to understand biology and social systems. To discuss this we must first define the terms (The American Heritage Dictionary). Holism is a theory or belief emphasizing the importance of the whole and the interdependence of its parts. In classical mechanics, for example, we understand the solar system in terms of its parts (the sun and the planets), and the interactions (“relationships”) are nonlinear. In quantum mechanics we understand complicated molecules like DNA in terms of the binding of smaller molecules. The genetic code is understood in terms of its building blocks: the four letter (computer) alphabet constructed from the bases A, C, G, and T. One understands the bases in terms of simpler molecules, the molecules in terms of atoms, and the atoms in terms of electrons and nuclei. This is reductionism: everything can be understood to be constructed systematically from electrons and positively charged nuclei. Yet, there is something that we cannot calculate from first principles using quantum mechanics: the behavior or the genes as a classical computer with three-letter words constructed from a four-letter alphabet. Quantum theory is linear, and the phase coherence cannot be destroyed from within, meaning that classical behavior cannot be derived from quantum theory without introducing a nonquantum assumption of destruction of phase coherence. This leads into the famous measurement problem clarified by von Neumann.
Reductionism and holism It was a fad in certain circles in the 1990s to announce that “reductionism is dead,” and that holism is necessary in order to understand biology and social systems. To discuss this we must first define the terms (The American Heritage Dictionary). Holism is a theory or belief emphasizing the importance of the whole and the interdependence of its parts. In classical mechanics, for example, we understand the solar system in terms of its parts (the sun and the planets), and the interactions (“relationships”) are nonlinear. In quantum mechanics we understand complicated molecules like DNA in terms of the binding of smaller molecules. The genetic code is understood in terms of its building blocks: the four letter (computer) alphabet constructed from the bases A, C, G, and T. One understands the bases in terms of simpler molecules, the molecules in terms of atoms, and the atoms in terms of electrons and nuclei. This is reductionism: everything can be understood to be constructed systematically from electrons and positively charged nuclei. Yet, there is something that we cannot calculate from first principles using quantum mechanics: the behavior or the genes as a classical computer with three-letter words constructed from a four-letter alphabet. Quantum theory is linear, and the phase coherence cannot be destroyed from within, meaning that classical behavior cannot be derived from quantum theory without introducing a nonquantum assumption of destruction of phase coherence. This leads into the famous measurement problem clarified by von Neumann.
Actualisation: when a system realises its potential.The term is borrowed from Carl Rogers, the founder of the person-centred approach to psychotherapy, who used it to refer to human development.Henry has used it to refer to how the physical world takes form.Atom: individual small particle.Frequently, used as a metaphor for the 'building blocks' of a larger whole.Atomism: the world view that everything is built up from smaller particles.Close in meaning to materialist reductionism, where materialist reductionism places more emphasis on the possibility to explain higher-order phenomena in terms of their constituent elements.Classical (world) view: the scientific paradigm on which most modern science is founded, where reality is assumed to consist of matter moved around by forces and matter is composed of particles.This view has been extended from physics and applied to most fields of science, including ones that cover more than the physical realm, such as biology, psychology, economics and social sciences generally.Coherence: mathematically, (quantum) waves can be described as the sum of multiple waves.This is known as superposition.Coherence refers to a state when the resulting wave form is stable in time and space.Under normal circumstances, interaction with the environment (i.e. the addition of other waves) leads the system to lose coherence over time and collapse from its superposed state.This process is known as decoherence.Complementarity Principle: principle from quantum physics that states that (quantum) particles have complementary properties that cannot be observed at the same time, such as wave and particle or position and momentum.Conceptually closely related to the uncertainty principle.Consciousness: often used synonymously with awareness.There are many ways to define consciousness, and this book follows
Abstract Quantum mechanics is often said to entail holism—that wholes are more than just the sum of their parts—and hence violate Humean supervenience. Certainly an entangled state cannot readily be interpreted in terms of the properties of the individual particles involved. But there is no clear general argument from quantum mechanics to holism. Still, each of the three major interpretations of quantum mechanics—Bohm, GRW, and many worlds—embodies some form of holism. One might try to rescue Humean supervenience by moving to high-dimensional representation of physical systems, or by constructing a theory with backward-in-time causation, but it is unclear if such strategies will succeed. If holism is accepted, some argue further that there are no individuals at the fundamental physical level: Either relations are fundamental, or the whole universe is fundamental. The arguments for these positions are assessed and found to be wanting.
Those defile the purity of mathematical and philosophical truthy who confound real quantities with their relations and sensible measures. —ISAAC NEWTON, Principia Before we say anything about quantum mechanics, let us take a quick look at the Newtonian (or ‘classical’) view of the physical universe. According to that view, nature consists of an enormous number of particles. When Newtonian physics is combined with the theory of the electromagnetic field, it becomes convenient to think of these particles as dimensionless (even if there is a kind of conceptual strain involved in trying to think of something as having a mass but not any size ), and as possessing electrical properties – negative charge, or positive charge, or neutrality. This leads to the well-known ‘solar system’ view of the atom – with the electrons whirling around the nucleons (neutrons and protons) just as the planets whirl around the sun. Out of atoms are built molecules; out of molecules, macroscopic objects, scaling from dust motes to whole planets and stars. These latter also fall into larger groupings – solar systems and galaxies – but these larger structures differ from the ones previously mentioned in being held together exclusively by gravitational forces. At every level, however, one has trajectories (ultimately that means the possibility of continuously tracing the movements of the elementary particles) and one has causality (ultimately that means the possibility of extrapolating from the history of the universe up to a given time to its whole sequence of future states).
Classical mechanics, which gives a fairly accurate description of large systems (e.g., solar system) as also of mechanical systems in our every day life, however, breaks down when applied to small (microscopic) systems such as molecules, atoms and nuclei. For example, (1) classical mechanics cannot even explain why the atoms are stable at all. A classical atom with electrons moving in circular or elliptic orbits around the nucleus would continuously radiate energy in the form of electromagnetic radiation because an accelerated charge does radiate energy. As a result the radius of the orbit would become smaller and smaller, resulting in instability of the atom. On the other hand, the atoms are found to be remarkably stable in practice. (2) Another fact of observation that classical mechanics fails to explain is wave particle duality in radiation as well as in material particles. It is well known that light exhibits the phenomena of interference, diffraction and polarization which can be easily understood on the basis of wave aspect of radiation. But light also exhibits the phenomena of photo-electric effect, Compton effect and Raman effect which can only be understood in terms of corpuscular or quantum aspect of radiation. The dual behavior of light, or radiation cannot be consistently understood on the basis of classical concepts alone or explained away by saying that light behaves as wave or particle depending on the kind of experiment we do with it (complementarity). Moreover, a beam of material particles, like electrons and neutrons, demonstrates wave-like properties (e.g., diffraction). A brief outline of phenomena that require quantum mechanics for their understanding follows.
In quantum mechanics the properties of a composite system can be divided into properties which are reducible to the properties of the subsystems of the composite and properties which are irreducible to those subsystem properties. The irreducible properties are called holistic and emerge when one describes the system as a whole. In this chapter I show that the bi and spectral modal interpretations can ascribe the holistic properties to composites but, in general, fail to reproduce the relations between the reducible properties of a composite and the properties of the subsystems. The atomic modal interpretation, on the other hand, fails to ascribe the holistic properties but is much more successful in reproducing the relations between the reducible properties and the subsystem properties. I discuss whether these failures harm the empirical adequacy and the metaphysical tenability of modal interpretations. Holistic properties of composite systems The basic principle of reductionism, that all the properties of composite systems are amalgamates of the properties of the subsystems of these composites, has triumphed so much in classical physics that I find it difficult to come up with a clear example of a classical property that cannot be taken as a complex of the subsystem properties. So, in order to make a case for the idea that composites can also possess, in addition to reducible properties, so-called holistic properties which cannot be reduced to the properties of the subsystems, one has to move outside physics or to draw upon some counterfactual development of physics.
Introduction Key features of quantum mechanics are the uncertainty principle, wave–particle duality, quantization of energies and the modification of classical probability laws. Biology is concerned with how natural systems function – from understanding how genetically coded information is replicated, to attaining a mechanistic model for complex multistep reactions. Recently researchers have been asking whether quantum mechanics, normally the domain of physics, is also needed to understand some biological processes. This field includes fascinating developments in theory and experiment, as well as multidisciplinary discussion, and the state-of-the-art is documented in this book. Erwin Schrödinger, in his famous book What is Life ? (Schrödinger, 1944), noted that quantum mechanics accounts for the stability of living things and their cellular processes because of our understanding, via quantum mechanics, of the stability and structure of molecules. The fact that quantum effects create, sometimes large, energy gaps between different states of a chemical system is also important. Such energy gaps, between electronic energy levels, enable living organisms to capture and store the energy carried from the sun by photons, and to visualize the world around them via optically induced chemical reactions. Davydov's view in Biology and Quantum Mechanics (Davydov, 1982) was that quantum mechanics is most relevant for isolated systems in pure states and therefore is of little importance for biological systems that are in statistical states at thermal equilibrium.