Where opposites – hopefully – not quite collide as strongly any longer – From reductionism and holism to „contextualism“
In discussions onthe theory and philosophy of science the heat can quickly reachelevated levels, especially in those taking place at cocktail partiesafter 10pm between scientists and those who display alesser degree of appreciation for the sobriety and rigor of the scientific method. At the center of the controversy then often lies a point of view, according to which any physical, biological or even social system can be completely understood by an analysis of the features of its individual components. Philosophical terminology refers to this view as „reductionism“. The physicist and Nobel laureate Steven Weinberg summarized it as follows:
If all the science is complete, all the explanation arrows will point downward, from societies to people to organs to cells to biochemistry to the chemistry to physics and ultimately to the final theory of nature.
In the public discourse (including the abovementioned cocktail parties) this expression too often carries a rather vague meaning. In most cases it comes with a strongly negative connotation,its opponentsequating it with equally negative terms such as „materialism“ (all phenomena of the world can be attributed to matter and reduced to its laws) or „scientism“ (all phenomena and meaningful questions can be exclusively captured by the scientific method). Citing Max Weber’s description of the „scientific disenchantment of the world“, they argue that an increasingly more broadly operatingscience occupies more and more aspects of human life and thus degradesnon-scientific approaches to understanding the world. At last reductionism becomes a dogma of „imperialist science“, they claim.A counter-position is the philosophical concept of „holism“ calling for an “all-inclusive” approach summarized by the much-quoted phrase „the whole is greater than the sum of its parts“.
The conflict between reductionism and holism goes back to the times of the European Enlightenment and the adjacent period of the Romantic era. While quite a few philosopher of the Enlightenment,in their euphoria about the new Newtonian description of nature, went as far as describing animals or even humans as reductively explainable machines (most notably Julien Offray de La Mettrie in his book „L’homme machine (1748; English:“ The Man-machine“)), the Romantics emphasized an often cited mystical experience of “feeling part of a greater whole „. The latter formulated the philosophical notion of an integration of opposites into a unity in which at last all contradictions between seemingly incompatible elements should resolve themselves beyond their apparent dualistic nature (such „polarities“ which at last become united at a higher level were generally an important part of early 19th century thoughts). Predecessors of this view we find already in the fragments of the pre-Socratic philosophers such as Parmenides and Heraclitus, where the opposites of being and non-being get resolved, in medieval mystics such as Meister Eckhart and Cusanus, where such unity is equal to the omnipresence of God, who at the same time represents the very location of such unity, and in the Mahayana Buddhist teachings of dependent origination (pratityasamutpada). References to transcendent entities like in medieval Christian mysticism or 19th centuryromanticism(and to some degree in today‘s “New Age” obscurantism) are for scientists very difficult to assess and methodically to accept. They therefore often argue in return that anti-reductionist intuitions are motivated by outdated metaphysical and theological prejudices.
In recent years an interesting new dimensionhas been added to this discussion, namely –and not entirely devoid of irony –on the part of physics,which previously had been most closely associated with reductionism. The coined term in this context has meanwhile attainedcertain prominence in philosophical and scientific jargon: „emergence“. A system is emergent, if it possesses properties which cannot (a least not obviously)be derived from any properties of its individual components. This makes a reduction very difficult or even eliminates any possibility of it. Examples from physics are paramagnetism (spontaneous magnetization of a substance in an external magnetic field), superconductivity, super fluidity (state of a liquid without any internal friction), phase transitions (such as freezing or melting of water), the fractional quantum Hall effect, and a few more phenomena of quantum physics. They all originate in macroscopic systems, where only a few determinants govern the overall behavior of many-particles-systems – so-called „order parameter“, which can change their sizes very suddenly. Many properties of solids such as solidity or elasticity only arise by the interaction of very many atoms. For single particles these concepts deem simply pointless.
In this context, a further termappears increasingly often, which was originally coined by the confusing nature of quantum physics: „contextuality“. Since the 1920s, physicists have known that quantum objects have no independent form of being, at least none that can be easily illustrated or portrayed. Only by interacting with an environment they receive their concrete manifestation and form. In other words, quantum objects have no reality by themselves, but only a „contextuallydefined” existence, i.e. from the specific context of their environment. Biologists in contrast have known the phenomenology of emergence and contextuality for some time before. They know that at higher levels of organization characteristics occur, which cannot be derived from lower-level components. For example, the behavior of a single ant is quite simple. They follow clear, almost mechanical rules of foraging, nesting, olfactory reactions, etc. Together with, i.e. in the context of many ants, however, they create a colony, which may display a surprisingly complex behavior and can even adapt to changing external conditions.
Digging deeper into the phenomenology of life, even the properties of living cells are not exclusively defined by the cells themselves i.e.they cannot be understood from its properties and those of its constituents alone. Without consideration of external circumstances, i.e. the context in which a cell lives as nutritional environment, pH-values, other cells, etc.,the behavior of a cell can hardly be determined. And genetic researchers know meanwhile, the same even applies to levels below the cell. They are now able to determine external, i.e.not DNA-encoded factors, which control the activity of individual genes. In other words, without being explicitly present in the genotype, these factors outside genetic expression affect the phenotype. In connection with corresponding (hereditary) variations in the genome function, which act in addition to the directgenetic expressions given by the DNA sequence, and which often find their origin in environmental circumstances the living being is exposed to, biologists speak of „epigenetics“. Epigenetic mechanisms show what psychologists, educators and sociologists have long claimed: living beings are far more than the results of their genes. They receive their qualities, skills, and opportunities by interacting with the environment they live in.
Thus the discussion on reductionism and holism today resonates in much more nuanced tones. However, also in the 21st century the discussions about the phenomena in nature hardly follow,as called for by thinkers in the romantic era, the primacy of sensations, feelings and mystical intuition. And the „cold and artificial experiment“ remains the scientists’ instrument of choice for obtaining deeper truths of life and the world. At the same time the scientists have recognized that their objects of investigation can produce phenomena and processes that exhibit self-regulatory dynamics, which can no longer be assessed solely from the properties of their components. Individual systems can, depending on their environment, display a very specific and idiosyncratic behavior. Thus a physical system may in a very non-mystical way be „part of a larger whole.”
However, the anti-reductionists continue to be able to refer to some fields that are not yet scientifically assessable and which can, even by those who consider them as principally scientifically describable,hardly be characterized by a reduction to simple units.For example, the consciousness or the mind is often regarded as a phenomenon thatprincipallyeludes a purely scientific or even reductionist description. Philosophers see the reason for this in the fact that mental states have the property of “being experienced in certain ways”. If you hold your hand in hot water, not only specific biological processes take place, but it simply hurts, too. Biological processes alone make it difficult if not impossible to understand why we experiencesomething like pain. At a higher level the moral evaluation of actions can hardly be described scientifically. This is because moral concepts are normative, in contrast to the descriptive nature of scientific descriptions. The same applies to aesthetic considerations.
A more than 200-year-long discussion is thus ongoing. But those who closely followed the arguments and developments in this discussion may realize that the battle lines are no longer quite as well defined as 200 or even 100 years ago. Neither should science be polemically referred to as “imperialistically-indoctrinate“, nor should anti-reductionist intuition be automatically identified with outdated metaphysical and theological motifs. It is definitely worthwhile for both sides to make the necessary effort for a more careful differentiation.