The Demeaning of Life...Chapter 6. The Day Vitalism Died

Our understanding of the world is built up of innumerable layers. Each layer is worth exploring, as long as we do not forget that it is one of many. Knowing all there is to be known about one layer—a most unlikely event—would not teach us much about the rest. The integration of the enormous number of bits of information and the resulting vision of nature take place in our minds; but the human mind is easily deceived and confused, and the vision of nature changes every few generations. It is, in fact, the intensity of the vision that counts more heavily than its completeness or its correctness. I doubt that there is such a thing as a correct view of nature, unless the rules of the game are stated clearly, undoubtedly, there will later be other games and other rules.

                                                          Erwin Chargaff, Heraclitean Fire

Up until 1953 it was still possible to believe that there was something fundamentally and irreducibly mysterious in living protoplasm. No longer. Even those philosophers who had been predisposed to a mechanistic view of life would not have dared hope for such total fulfillment of their wildest dreams. 

                                                                Richard Dawkins, River Out of Eden

Late in life, Jacques Monod asserted during an interview, “Anything can be reduced to simple, obvious, mechanical interactions. The cell is a machine; the animal is a machine; man is a machine.” How did the mechanistic viewpoint come to dominate biological thinking to the extent that a famous scientist could make such a manifestly one-sided statement? As always, turning to history is a good place to start looking for answers. 

Beginning around Aristotle’s time (4^th century B.C.), philosophers believed that the orderly way in which organisms grow and develop could be credited to a vitalistic principle, an influence that was beyond human comprehension and thus considered not within reach of investigation. This vital “force” was a manner of identifying the cause behind a prevailing worldview which, in pre-Christian times (and with roots going back at least as far as ancient Egypt), could broadly be considered pantheistic.[1] 

As the scientific revolution gathered steam it increasingly became apparent that most observed phenomena were completely natural and could be understood and described without invoking mystical forces. (Well into the 19^th century, in certain fields—embryology, for instance—the intermingling of naturalistic and supernatural explanations was still practiced by reputable scientists.) Galileo, Kepler, and Newton in turn demonstrated the inestimable worth of mathematics as a way of describing the cosmos, which contributed to an even more compellingly mechanistic worldview. Ernst Mayr, in his last book, This is Biology, describes the intellectual mood of this era: 


The rapid development of physics…after [the Renaissance] carried the Scientific Revolution a step further, turning the more general mechanicism of the early period into a more specific physicalism, based on a set of concrete laws about the workings of both the  heavens and the earth…. The physicalist movement  had the enormous merit of refuting much of the magical thinking that had generally characterized the preceding centuries. Its greatest achievement perhaps was providing a natural explanation of physical phenomena and eliminating much of the reliance on the supernatural that was previously accepted by virtually everybody. If mechanism, and particularly its outgrowth into physicalism, went too far in some respects, this was inevitable for an energetic new movement.[2]

Substantial numbers of people who cared deeply about such matters clung to an enduring intuitive sense that living things possessed qualities that could never be accounted for by physicalism (defined as the belief that physical entities are all that exist). A sort of countermovement resulted, manifesting in different forms at different times; this philosophical vitalism originated in the 17^th century and held sway until the mid-1800s. Though never a unified “movement,” it was a reaction to mechanistic thinking, and its proponents focused on various issues they felt physicalism failed to take into account: the origin of adaptations and behaviors, the mystery of development and regeneration…the very nature of what animated living things. 

The influential French philosopher Henri Bergson, shortly after the beginning of the 20^th century, popularized the notion of an élan vital. The idea briefly took on a mantle of scientific respectability in the early 1900s when German embryologist Hans Driesch discovered that embryos, mutilated in the earliest stages of their cellular multiplication, could recover and develop into more or less normal organisms. This, and other remarkable aspects of growth and development, led him to that the emergence of the correct form of any organism—in all its intricate complexity—must be under the  influence of some guiding life force, which he called entelechy. (He actually borrowed this term from Aristotle who coined it to mean “the condition of a thing whose essence is fully realized; actuality.”) 

Driesch knew well that the ordering properties of entelechy were in conflict with everyday physical forces and laws and emphasized in his writings that it was a natural (as opposed to a mystical or metaphysical) factor that acted on normal developmental processes. He suggested that, whatever it was, entelechy operates by influencing the timing of molecular interactions in a manner that promotes a cooperative, holistic pattern of development. While his ideas were never absolutely discredited, they never advanced scientifically, being resistant not only to some form of experimental proof, but even to real conceptual coherence—virtually inevitable, given their nebulous nature. Driesch’s ideas have subsequently been revisited by others in slightly different forms but for similar reasons never gained traction.

Contrary to how naïve any vitalistic theories appear today, vitalism was, in its time, a legitimate alternative—not just to mechanism but to the more sophisticated physicalism as well. Adherents of both schools were passionate in their beliefs and there were repeated periods of struggle between the ideologies. After all, physicalists of the mid- to late-19^th century employed their own nebulous concepts and poorly defined terms to describe phenomena that could not yet be understood. In addition, they often failed to address the main concerns of their intellectual adversaries.[3] Nevertheless, with  unrelenting scientific advances, vitalism gradually faded into the background, in large part due to increasingly being seen as a metaphysical program unable to come up with coherent theories subject to being tested. 

There are some who feel that vitalism is an inescapable feature of biology, dressed in new clothes. Maverick biologist Rupert Sheldrake holds that Dawkins’ selfish gene metaphor is vitalism in disguise. He points out that “[m]echanists expel purposive vital factors from living animals and plants, but then they reinvent them in molecular guises. One form of molecular vitalism is to treat the genes as purposive entities with goals and powers that go far beyond those of a…chemical like DNA. The genes become molecular entelechies…[that are] selfish, ruthless and competitive.”

 The complex history of cytology (the study of cells) exemplifies the transition  between a vitalistic and mechanistic conception of living things—from initial discovery through all the steps leading to an understanding of the cell’s central place in nature.
 

Cells were unknown before English polymath Robert Hooke, peering through an early microscope at a thin slice of cork, saw tiny and apparently empty four-sided compartments that reminded him of monks’ cubicles. Hooke had no idea what these minute chambers were but certainly would not have imagined he was observing the building blocks of all living things. Early microscopists were still influenced by a holdover from ancient Greek philosophy—atomism—and assumed that the basic constituents of life were invisible, indivisible, indestructible particles. (Not to be confused with the modern, scientific conception of atoms.)
 

By the end of the 18^th century it was an accepted fact that cells were the fundamental components of plants but it was not until the 1820s that French botanist Henri Dutrochet first proposed that they were not just structural entities but physiological as well. Owing to his discovery of osmosis[4] and careful studies of respiration,[5] Dutrochet is considered the father of cell physiology. A confirmed anti-vitalist, his work was always focused on demonstrating that physics and chemistry lay behind life processes.
 

Dutrochet’s work led to a more wide-ranging cell theory that was independently put forward by two Germans: botanist Matthias Schleiden and a colleague, zoologist Theodor Schwann. In 1838, Schleiden proposed that all parts of a plant were composed of cells and that new cells arose from the nuclei of older cells, which were formed in some sort of unspecified crystallization process. (While the gist of Schleiden’s premises were correct, almost all the details were based on erroneous speculations.) The following year, Schleiden and Schwann had a conversation involving plant cells’ nuclei. Schwann recalled having observed similar structures in tissues from frog embryos.[6]  Recognizing an important finding, they compared resemblances and confirmed a connection between the two phenomena. Schwann realized that animals as well as plants were composed of cells and that cells—not organs and tissues—were the elementary units of life. Shortly thereafter he published a paper on his ground-breaking hypothesis. Mayr: “Few publications in biology have ever caused such a sensation as Schwann’s magnificent monograph. It demonstrated that animals and plants consist of the same building blocks—cells—and that a unity therefore exists throughout the entire organic world…. It was a vigorous endorsement of reductionist thinking.”
 

By 1852, after years of painstaking observation, the Polish embryologist Robert  Remak concluded that binary fission—that is, dividing in two—was the only means by which animal cells could multiply. He established without doubt that new cells were not the result of productions of the nuclei or unformed substances in intercellular spaces (the erroneous hypotheses of Schleiden and Schwann, respectively). His investigations, while slow to gain acceptance, paved the way to an entirely new model of how organisms developed. Unacknowledged in his lifetime (and even to this day), it was Remak’s work that helped clarify the muddled views surrounding animal cells’ origins. 


Eminent pathologist Rudolf Virchow, after initially doubting Remak’s findings, became an enthusiastic supporter. (Virchow famously popularized the Latin aphorism, Omnis cellula e cellula—“Every cell from another cell.”) By the mid-1850s, in addition to writing the time’s seminal work on pathology, a series of well-received lectures by the charismatic scientist helped lead to wider acceptance of this new cell theory—further eroding belief in spontaneous generation, which still held sway at the time. Virchow was an outspoken advocate of mechanism and early promoter of the concept that life is essentially a mechanical process. His popularization of these ideas helped expand research into the finer details of cell division, which was then being greatly aided by improved microscopes and novel staining techniques (that visually enhance specific parts of the generally colorless cellular interior by means of a number of chemical agents and treatments). 


Biologist Walther Flemming studied the process of cell division and, thanks to new staining methods, was the first person to see threadlike structures (later to be named “chromosomes”) in the nuclei of cells taken from salamanders. Flemming observed these “colored bodies” and their distribution in daughter cells, naming this process (mitosis) in a detailed report of his findings in 1879. Though unable to actually witness the chain of events, his important book, Cell Substance, Nucleus and Cell Division, published four years later, provided the first detailed account of cell division. Also of note is that Flemming—in common with all his peers—was unfamiliar with Gregor Mendel;  otherwise, he may well have perceived the link between chromosomes and heredity.[7]
 

At the beginning of the 20^th century, cell theory had achieved a degree of coherence: it was recognized that both plant and animal tissues are composed of cells; that new cells arise through binary fission; that all organisms start out as a single cell formed by the union of egg and sperm; that these germ cells each carried a set of hereditary elements, or factors (later, genes); that these factors were duplicated during cellular division, becoming two identical sets of genetic material (chromosomes); and that each new cell thus received a copied set of factors from the parent cell. It was a start. 


The physicalist viewpoint was further bolstered by the discoveries of German-born physiologist Jacques Loeb. In 1891 Loeb immigrated to the United States where, along with several successive professorships, he taught physiology (while also conducting research on various marine invertebrates) at the now-famous biological laboratory in Woods Hole, Massachusetts. Already long committed to a “biological engineering” approach in his experimental work, Loeb’s landmark book The Mechanistic Conception of Life (1912) described experiments involving sea urchin eggs whose development he was able to induce without their first being fertilized. His results (initially attained in 1899) provided dramatic evidence supporting the mechanistic model of cellular functions. This procedure later became routine, but in those simpler times his results created a sensation; newspaper headlines all but claimed that Loeb could create life in a test tube.[8] He became one of the most famous scientific figures in America, and was influential in helping biology transition to a largely experimental science.
 

Mendel’s recently exhumed research results provided solid evidence that heredity was indeed controlled by molecules, providing a significant boost to Loeb’s (and other committed mechanists’) investigations. And it was Loeb who insightfully recognized that Mendel’s findings pointed the way to biology’s next big mission: to discover the chemical substances within chromosomes that were responsible for passing on     hereditary traits. Though it may have taken longer than expected, biochemists James Watson and Francis Crick made a monumental breakthrough in the early 1950s that would all but finish off vitalism. Boyce Rensberger noted that “by applying a purely  reductionist approach to the study of life, they would vindicate the mechanist view spectacularly with the discovery of…DNA and the cracking of the genetic code.” 


That tremendous leap forward captivated the literate world. It epitomized science at its best and what a new breed of scientists were capable of and, regardless of their level of comprehension, everyone was talking about the wonderful double helix.  A torrent of breakthroughs followed, along with increased research funding and the development of truly impressive new technologies. Thanks to enthusiastic media attention, in addition to popular books written by intriguing men-of-learning, the public was led to a widespread and virtually unquestioned perception of cells as tiny machines—very complicated machines, yes, but comprehensible nonetheless. 


In addition, by the mid 1800s, science had assumed an aura of authority that matched the climate of those times. A new picture of reality emerged—one that attested to a world operating by simple, rational laws: predictable, reasonable, and comprehensible (even if this was not always strictly the case). Importantly, it was a reality no longer seen as inherently mysterious—somewhat like the Newtonian world-view, but a version charged with new power and accessibility through being extended to encompass the study of life. The establishment of relativity, Heisenberg’s uncertainty principle, and quantum theory injected mystique back into the universal view but their effect did little to dent a new confidence in Earth-bound empirical science. 
                                 

The announcement of DNA’s discovery via a two page article in the April 1953 issue of Nature began a whole new chapter of modern life; from a cultural standpoint, science’s role in everyday living was a perfect addition to the atmosphere of optimism and progress following WW II’s end. Religious views continued to be influenced by the lasting impact of Darwin’s radical ideas; as his theory of natural selection gained ever greater acceptance, people felt the wider effects of being further liberated from the church’s stifling dictates and lingering superstitions (a course unwittingly first set in motion by Newton). Even devoutly religious people saw the light and were tentatively embracing a perspective permitting both God and science to illuminate their worldview. The never-ending introduction of fantastic new machines and technologies, plus an escalating adoption of mechanical terminology (and, later, computer jargon) to describe biological processes, lent credence to the notion that living things are basically machines as well—a supposition that has only grown stronger with passing time. Even after three centuries of determined study, our overall conception of nature is far from settled. The whole enterprise is a work in progress and our current views, the product of history, mental effort, sweat, and serendipitous accident. One thing is certain: life is a curious and extraordinarily convoluted affair.                                
 

©2017 Tim Forsell

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[1] Pantheism is the belief that the Universe (or nature as the totality of everything) is identical with divinity, or that everything composes an all-encompassing, immanent god. Pantheists thus do not believe in a distinct personal or anthropomorphic god. Such concepts date back thousands of years, and some religions in the East continue to contain pantheistic elements.

[2] An aside: this was Mayr’s last book, published when he was ninety-three.

[3] Mayr again: “It is ironic that the physicalists attacked the vitalists for invoking an unanalyzed ‘vital force,’ and yet in their own explanations they used such equally unanalyzed factors as ‘energy’ and ‘movements.’ The definitions of life and the descriptions of living processes formulated by the physicalists often consisted of utterly vacuous statements. For example, the physical chemist Wilhelm Ostwald defined a sea urchin as being, like any other piece of matter, ‘a spatially discrete cohesive sum of quantities of energy.’… [Pioneer embryologist] Wilhelm Roux…stated that development is ‘the production of diversity owing to the unequal distribution of energy.’ These [and other] physicalists never noticed that their statements about energy and movement did not really explain anything at all.” 

[4] The tendency of a solvent—such as water—to diffuse from a region where dissolved substances are less concentrated to one where they are more so. Unless checked, osmosis continues until the concentrations of the substances are in equilibrium.

[5] The movement of oxygen (from air) to tissues and cells and subsequent elimination of carbon dioxide (as a waste product).

[6] It should be noted that little was then known about animal cells; in contrast to plants, it was much harder to prepare animals’ relatively delicate tissues for study under a microscope. Also, animal cells are typically much smaller than those of plants.

[7] Two decades passed before the re-emergence of Mendel’s work revealed the significance of Flemming’s own important findings. His identification of chromosomes and mitosis are thought to be among the 100 most important scientific discoveries.

[8] Humorous historical facts worth knowing: The press’ coverage of Loeb’s discovery evidently gave birth to the (mis)use of that hackneyed expression. According to Boyce Rensberger, “Loeb’s experiments, in a seaside laboratory and on marine organisms, became so mixed up in the popular mind with the allegedly mysterious powers of the sea that unmarried women were advised not to bathe in the ocean. Childless couples, on the other hand, rushed hopefully to beach resorts. Loeb even received letters from desperate couples asking him to give them a child.”