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Beyond the “Mechanism” Metaphor in Biology

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In a previous post, I discussed the frequent use of the “mechanism” metaphor in the sciences. I argued that while this metaphor was useful in spurring research into cause-and-effect patterns in physical and biological entities, it was inadequate as a descriptive model for what the universe and life is like. In particular, the “mechanism” metaphor is unable to capture the reality of change, the evidence of self-driven progress, and the autonomy and freedom of life forms.

I don’t think it’s possible to abandon metaphors altogether in science, including the mechanism metaphor. But I do think that if we are to more fully understand the nature of life, in all its forms, we must supplement the mechanism metaphor with other, additional conceptualizations and metaphors that illustrate dynamic processes.

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David Bohm (1917-1992), one of the most prominent physicists of the 20th century, once remarked upon a puzzling development in the sciences: While 19th century classical physics operated according to the view that the universe was a mechanism, research into quantum physics in the 20th century demonstrated that the behavior of particles at the subatomic level was not nearly as deterministic as the behavior of larger objects, but rather was probabilistic. Nevertheless, while physicists adjusted to this new reality, the science of biology was increasingly adopting the metaphor of mechanism to study life. Remarked Bohm:

 It does seem odd . . . that just when physics is thus moving away from mechanism, biology and psychology are moving closer to it. If this trend continues, it may well be that scientists will be regarding  living and intelligent beings as mechanical, while they suppose that inanimate matter is too complex and subtle to fit into the limited categories of mechanism. But of course, in the long run, such a point of view cannot stand up to critical analysis. For since DNA and other molecules studied by the biologist are constituted of electrons, protons, neutrons, etc., it follows that they too are capable of behaving in a far more complex and subtle way than can be described in terms of mechanical concepts. (Source: David Bohm, “Some Remarks on the Notion of Order,” in Towards a Theoretical Biology, Vol. 2: Sketches, ed. C.H. Waddington, Chicago: Aldine Publishing, p. 34.)

According to Bohm, biology had to overcome, or at least supplement, the mechanism metaphor if it was to advance. It was not enough to state that anything outside mechanical processes was “random,” for the concept of randomness was too ill-defined to constitute an adequate description of phenomena that did not fit into the mechanism metaphor. For one thing, noted Bohm, the word “random” was often used to denote “disorder,” when in fact it was impossible for a phenomenon to have no order whatsoever. Nor did unpredictability imply randomness — Bohm pointed out that the notes of a musical composition are not predictable, but nonetheless have a precise order when considered in totality. (Ibid., p. 20)

Bohm’s alternative conceptualization was that of an open order, that is, an order that consisted of multiple potential sub-orders or outcomes. For example, if you roll a single die once, there are six possible outcomes and each outcome is equally likely. But the die is not disordered; in fact, it is a precisely ordered system, with equal length dimensions on all sides of the cube and a weight equally distributed throughout the cube. (This issue is discussed in How Random is Evolution?) However, unlike the roll of a die, life is both open to new possibilities and capable of retaining previous outcomes, resulting in increasingly complex orders, orders that are nonetheless still open to change.

Although we are inclined to think of reality as composed of “things,” Bohm argued that the fundamental reality of the universe was not “things” but change: “All is process. That is to say, there is no thing in the universe. Things, objects, entities, are abstractions of what is relatively constant from a process of movement and transformation. They are like the shapes that children like to see in the clouds . . . .” (“Further Remarks on Order,” Ibid., p. 42) The British biologist C.H. Waddington, commenting on Bohm, proposed another metaphor, borrowed from the ancient Judeo-Christian sectarian movement known as Gnosticism:

‘Things’ are essentially eggs — pregnant with God-knows-what. You look at them and they appear simple enough, with a bland definite shape, rather impenetrable. You glance away for a bit and when you look back what you find is that they have turned into a fluffy yellow chick, actively running about and all set to get imprinted on you if you will give it half a chance. Unsettling, even perhaps a bit sinister. But one strand of Gnostic thought asserted that _everything_ is like that. (C.H. Waddington, “The Practical Consequences of Metaphysical Beliefs on a Biologist’s Work,” Ibid., p. 73)

Bohm adds that although the mechanism metaphor is apt to make one think of nature as an engineer or the work of an engineer (i.e., the universe as a “clock”), it could be more useful to think of nature as an artist. Bohm compares nature to a young child beginning to draw. Such a child attempting to draw a rectangle for the first time is apt to end up with a drawing that resembles random or nearly-random lines. Over time however, the child gathers visual impressions and instructions from parents, teachers, books, and toys of what shapes are and what a rectangle is; over time, with growth and practice, the child learns to draw a reasonably good rectangle. (Bohm, “Further Remarks on Order, Ibid., pp. 48-50) It is an order that appears to be the outcome of randomness, but in fact emerges from an open order of multiple possibilities.

 

The American microbiologist Carl. W. Woese (1928-2012), who achieved honors and awards for his discovery of a third domain of life, the “archaea,” also rejected the use of mechanist perspectives in biology. In an article calling for a “new biology,” Woese argued that biology borrowed too much from physics, focusing on the smallest parts of nature while lacking a holistic perspective:

Let’s stop looking at the organism purely as a molecular machine. The machine metaphor certainly provides insights, but these come at the price of overlooking much of what biology is. Machines are not made of parts that continually turn over, renew. The organism is. Machines are stable and accurate because they are designed and built to be so. The stability of an organism lies in resilience, the homeostatic capacity to reestablish itself. While a machine is a mere collection of parts, some sort of “sense of the whole” inheres in the organism, a quality that becomes particularly apparent in phenomena such as regeneration in amphibians and certain invertebrates and in the homeorhesis exhibited by developing embryos.

If they are not machines, then what are organisms? A metaphor far more to my liking is this. Imagine a child playing in a woodland stream, poking a stick into an eddy in the flowing current, thereby disrupting it. But the eddy quickly reforms. The child disperses it again. Again it reforms, and the fascinating game goes on. There you have it! Organisms are resilient patterns in a turbulent flow—patterns in an energy flow. A simple flow metaphor, of course, fails to capture much of what the organism is. None of our representations of organism capture it in its entirety. But the flow metaphor does begin to show us the organism’s (and biology’s) essence. And it is becoming increasingly clear that to understand living systems in any deep sense, we must come to see them not materialistically, as machines, but as (stable) complex, dynamic organization. (“A New Biology for a New Century,” Microbiology and Molecular Biology Reviews, June 2004, pp. 175-6)

A swirling pattern of water is perhaps not entirely satisfactory as a metaphoric conceptualization of life, but it does point to an aspect of reality that the mechanism metaphor does not satisfactorily capture: the ability of life to adapt.

Woese proposes another metaphor to describe what life was like in the very early stages of evolution, when primitive single-celled organisms were all that existed: a community. In this stage, cellular organization was minimal, and many important functions evolved separately and imperfectly in different cellular organisms. However, these organisms could evolve by exchanging genes, in a process called Horizontal Gene Transfer (HGT). This was the primary factor in very early evolution, not random mutation. According to Woese:

The world of primitive cells feels like a vast sea, or field, of cosmopolitan genes flowing into and out of the evolving cellular (and other) entities. Because of the high level of HGT [horizontal gene transfer], evolution at this stage would in essence be communal, not individual. The community of primitive evolving biological entities as a whole as well as the surrounding field of cosmopolitan genes participates in a collective reticulate [i.e., networked] evolution. (Ibid., p. 182)

It was only later that this loose community of cells increased their interactions to the point at which a phase transition took place, in which evolution became less communal and the vertical inheritance of relatively well-developed organisms became the main form of evolutionary descent. But horizontal gene transfer still continued after this transition, and continues to this day. (Ibid., pp. 182-84) It’s hard to see how these interactions resemble any kind of mechanism.

Tree of life showing vertical and horizontal gene transfers.

Source:  Horizontal gene transfer – Wikipedia

 

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So let’s return to the question of “vitalism,” the old theory that there was something special responsible for life: a soul, spirit, force, or substance. The old theories of vitalism have been abandoned on the grounds that no one has been able to observe, identify, or measure a soul, spirit, etc. However, the dissatisfaction of many biologists with the “mechanist” outlook has led to a new conception of vitalism, one in which the essence of life is not in a mysterious substance or force but in the organization of matter and energy, and the processes that occur under this organization. (See Sebastian Normandin and Charles T. Wolfe, eds., Vitalism and the Scientific Image in Post-Enlightenment Life Science, 1800-2010, p. 2n4, 69, 277, 294 )

As Woese wrote, organisms are “resilient patterns . . . in an energy flow.” In a previous essay, I pointed to the work of the great physicist Werner Heisenberg, who noted that matter and energy are essentially interchangeable and that the universe itself began as a great burst of energy, much of which gradually evolved into different forms of matter over time. According to Heisenberg, “Energy is in fact the substance from which all elementary particles, all atoms and therefore all things are made. . . .” (Physics and Philosophy, p. 63)

Now energy itself is not a personal being, and while energy can move things, it’s problematic to equate any moving matter as a kind of life. But is it not the case that once a particular configuration of energy/matter rises to a certain level, organized under a unified consciousness with a free will, then that configuration of energy/matter constitutes a spirit or soul? In this view, there is no vitalist “substance” that gives life to matter — it is simply a matter of energy/matter reaching a certain level of organization capable of (at least minimal) consciousness and free will.

In this view, when ancient peoples thought that breath was the spirit of life and blood was the sacred source of life, they were not that far off the mark. Oxygen is needed by (most) life forms to process the energy in food. Without the continual flow of oxygen from our environment into our body, we die. (Indeed, brain damage will occur after only three minutes without oxygen.) And blood delivers the oxygen and nutrients to the cells that compose our body. Both breath and blood maintain the flow of energy that is essential to life. It’s all a matter of organized energy/matter, with billions of smaller actors and activities working together to form a unified conscious being.

The Metaphor of “Mechanism” in Science

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The writings of science make frequent use of the metaphor of “mechanism.” The universe is conceived as a mechanism, life is a mechanism, and even human consciousness has been described as a type of mechanism. If a phenomenon is not an outcome of a mechanism, then it is random. Nearly everything science says about the universe and life falls into the two categories of mechanism and random chance.

The use of the mechanism metaphor is something most of us hardly ever notice. Science, allegedly, is all about literal truth and precise descriptions. Metaphors are for poetry and literature. But in fact mathematics and science use metaphors. Our understandings of quantity, space, and time are based on metaphors derived from our bodily experiences, as George Lakoff and Rafael Nunez have pointed out in their book Where Mathematics Comes From: How the Embodied Mind Brings Mathematics into Being  Theodore L. Brown, a professor emeritus of chemistry at the University of Illinois at Urbana-Champaign, has provided numerous examples of scientific metaphors in his book, Making Truth: Metaphor in Science. Among these are the “billiard ball” and “plum pudding” models of the atom, as well as the “energy landscape” of protein folding. Scientists envision cells as “factories” that accept inputs and produce goods. The genetic structure of DNA is described as having a “code” or “language.” The term “chaperone proteins” was invented to describe proteins that have the job of assisting other proteins to fold correctly.

What I wish to do in this essay is closely examine the use of the mechanism metaphor in science. I will argue that this metaphor has been extremely useful in advancing our knowledge of the natural world, but its overuse as a descriptive and predictive model has led us down the wrong path to fully understanding reality — in particular, understanding the actual nature of life.

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Thousands of years ago, human beings attributed the actions of natural phenomena to spirits or gods. A particular river or spring or even tree could have its own spirit or minor god. Many humans also believed that they themselves possessed a spirit or soul which occupied the body, gave the body life and motion and intelligence, and then departed when the body died. According to the Bible, Genesis 2:7, when God created Adam from the dust of the ground, God “breathed into his nostrils the breath of life; and man became a living soul.” Knowing very little of biology and human anatomy, early humans were inclined to think that spirit/breath gave life to material bodies; and when human bodies no longer breathed, they were dead, so presumably the “spirit” went someplace else. The ancient Hebrews also saw a role for blood in giving life, which is why they regarded blood as sacred. Thus, the Hebrews placed many restrictions on the consumption and handling of blood when they slaughtered animals for sacrifice and food. These views about the spiritual aspects of breath and blood are also the historical basis of “vitalism,” the theory that life consists of more than material parts, and must somehow be based on a vital principle, spark, or force, in addition to matter. 

The problem with the vitalist outlook is that it did not appreciably advance our knowledge of nature and the human body.  The idea of a vital principle or force was too vague and could not be tested or measured or even observed. Of course, humans did not have microscopes thousands of years ago, so we could not see cells and bacteria, much less atoms.

By the 17th century, thinkers such as Thomas Hobbes and Rene Descartes proposed that the universe and even life forms were types of mechanisms, consisting of many parts that interacted in such a way as to result in predictable patterns. The universe was often analogized to a clock. (The first mechanical clock was developed around 1300 A.D., but water clocks, based on the regulated flow of water, have been in use for thousands of years.) The great French scientist Pierre-Simon Laplace was an enthusiast for the mechanist viewpoint and even argued that the universe could be regarded as completely determined from its beginnings:

We may regard the present state of the universe as the effect of the past and the cause of the future. An intellect which at any given moment knew all of the forces that animate nature and the mutual positions of the beings that compose it, if this intellect were vast enough to submit the data to analysis, could condense into a single formula the movement of the greatest bodies of the universe and that of the lightest atom; for such an intellect nothing could be uncertain and the future just like the past would be present before its eyes. (A Philosophical Essay on Probabilities, Chapter Two)

Laplace’s radical determinism was not embraced by all scientists, but it was a common view among many scientists. Later, as the science of biology developed, it was argued that the evolution of life was not as determined as the motion of the planets. Rather, random genetic mutations resulted in new life forms and “natural selection” determined that fit life forms flourished and reproduced, while unfit forms died out. In this view, physical mechanisms combined with random chance explained evolution.

The astounding advances in physics and biology in the past centuries certainly seem to justify the mechanism metaphor. Reality does seem to consist of various parts that interact in predictable cause-and-effect patterns. We can predict the motions of objects in space, and build technologies that send objects in the right direction and speed to the right target. We can also methodically trace illnesses to a dysfunction in one or more parts of the body, and this dysfunction can often be treated by medicine or surgery.

But have we been overusing the mechanism metaphor? Does reality consist of nothing but determined and predictable cause-and-effect patterns with an element of random chance mixed in?

I believe that we can shed some light on this subject by first examining what mechanisms are — literally — and then examine what resemblances and differences there are between mechanisms and the actual universe, between mechanisms and actual life.

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Even in ancient times, human beings created mechanisms, from clocks to catapults to cranes to odometers. The Antikythera mechanism of ancient Greece, constructed around 100 B.C., was a sophisticated mechanism with over 30 gears that was able to predict astronomical motions and is considered to be one of the earliest computers. Below is a photo of a fragment of the mechanism, discovered in an ocean shipwreck in 1901:

 

Over subsequent centuries, human civilization created steam engines, propeller-driven ships, automobiles, airplanes, digital watches, computers, robots, nuclear reactors, and spaceships.

So what do most or all of these mechanisms have in common?

  1. Regularity and Predictability. Mechanisms have to be reliable. They have to do exactly what you want every time. Clocks can’t run fast, then run slow; automobiles can’t unilaterally change direction or speed; nuclear reactors can’t overheat on a whim; computers have to give the right answer every time. 
  2. Precision. The parts that make up a mechanism must fit together and move together in precise ways, or breakdown, or even disaster, will result. Engineering tolerances are typically measured in millimeters.
  3. Stability and Durability. Mechanisms are often made of metal, and for good reason. Metal can endure extreme forces and temperatures, and, if properly maintained, can last for many decades. Metal can slightly expand and contract depending on temperature, and metals can have some flexibility when needed, but metallic constructions are mostly stable in shape and size. 
  4. Unfree/Determined. Mechanisms are built by humans for human purposes. When you manage the controls of a mechanism correctly, the results are predictable. If you get into your car and decide to drive north, you will drive north. The car will not dispute you or override your commands, unless it is programmed to override your commands, in which case it is simply following a different set of instructions. The car has no will of its own. Human beings would not build mechanisms if such mechanisms acted according to their own wills. The idea of a self-willing mechanism is prolific in science fiction, but not in science.
  5. They do not grow. Mechanisms do not become larger over time or change their basic structure like living organisms. This would be contrary to the principle of durability/stability. Mechanisms are made for a purpose, and if there is a new purpose, a new mechanism will be made.
  6. They do not reproduce. Mechanisms do not have the power of reproduction. If you put a mechanism into a resource-rich environment, it will not consume energy and materials and give birth to new mechanisms. Only life has this power. (A partial exception can be made in the case of  computer “viruses,” which are lines of code programmed to duplicate themselves, but the “viruses” are not autonomous — they do the bidding of the programmer.)
  7. Random events lead to the universal degradation of mechanisms, not improvement. According to neo-Darwinism, random mutations in the genes of organisms are what is responsible for evolution; in most cases, mutations are harmful, but in some cases, they lead to improvement, leading to new and more complex organisms, ultimately culminating in human beings. So what kind of random mutations (changes) lead to improved mechanisms? None, really. Mechanisms change over time with random events, but these events lead to degradation of mechanisms, not improvement. Rust sets in, different parts break, electric connections fail, lubricating fluids leak. If you leave a set of carefully-preserved World War One biplanes out in a field, without human intervention, they will not eventually evolve into jet planes and rocket ships. They will just break down. Likewise, electric toasters will not evolve into supercomputers, no matter how many millions of years you wait. Of course, organisms also degrade and die, but they have the power of reproduction, which continues the population and creates opportunities for improvement.

There is one hypothetical mechanism that, if constructed, could mimic actual organisms: a self-replicating machine. Such a machine could conceivably contain plans within itself to gather materials and energy from its environment and use these materials and energy to construct copies of itself, growing exponentially in numbers as more and more machines reproduce themselves. Such machines could even be programmed to “mutate,” creating variations in its descendants. However, no such mechanism has yet been produced. Meanwhile, primitive single-celled life forms on earth have been successfully reproducing for four billion years.

Now, let’s compare mechanisms to life forms. What are the characteristics of life?

  1. Adaptability/Flexibility. The story of life on earth is a story of adaptability and flexibility. The earliest life forms, single cells, apparently arose in hydrothermal vents deep in the ocean. Later, some of these early forms evolved into multi-cellular creatures, which spread throughout the oceans. After 3.5 billion years, fish emerged, and then much later, the first land creatures. Over time, life adapted to different environments: sea, land, rivers, caves, air; and also to different climates, from the steamiest jungles to frozen environments. 
  2. Creativity/Diversification. Life is not only adaptive, it is highly creative and branches into the most diverse forms over time. Today, there are millions of species. Even in the deepest parts of the ocean, life forms thrive in an environment with pressures that would crush most life forms. There are bacteria that can live in water at or near the boiling point. The tardigrade can survive the cold, hostile vacuum of space. The bacteria Deinococcus radiodurans is able to survive extreme forms of radiation by means of one of the most efficient DNA repair capabilities ever seen. Now it’s true that among actual mechanisms there is also a great variety; but these mechanisms are not self-created, they are created by humans and retain their forms unless specifically modified by humans.
  3. Drives toward cooperation / symbiosis. Traditional Darwinist views of evolution see life as competition and “survival of the fittest.” However, more recent theorists of evolution point to the strong role of cooperation in the emergence and survival of advanced life forms. Biologist Lynn Margulis has argued that the most fundamental building block of advanced organisms, the cell, was the result of a merger between more primitive bacteria billions of years ago. By merging, each bacterium lent a particular biological advantage to the other, and created a more advanced life form. This theory was regarded with much skepticism at the time it was proposed, but over time it became widely accepted.  Today, only about half of the human body is made up of human cells — the other half consists of trillions of microbes and quadrillions of viruses that largely live in harmony with human cells. Contrary to the popular view that microbes and viruses are threats to human beings, most of these microbes and viruses are harmless or even beneficial to humans. Microbes are essential in digesting food and synthesizing vitamins, and even the human immune system is partly built and partly operated by microbes!  By contrast, the parts of a mechanism don’t naturally come together to form the mechanism; they are forced together by their manufacturer.
  4. Growth. Life is characterized by growth. All life forms begin with either a single cell, or the merger of two cells, after which a process of repeated division begins. In multicellular organisms, the initial cell eventually becomes an embryo; and when that embryo is born, becoming an independent life form, it continues to grow. In some species, that life form develops into an animal that can weigh hundreds or even thousands of pounds. This, from a microscopic cell! No existing mechanism is capable of that kind of growth.
  5. Reproduction. Mechanisms eventually disintegrate, and life forms die. But life forms have the capability of reproducing and making copies of themselves, carrying on the line. In an environment with adequate natural resources, the number of life forms can grow exponentially. Mechanisms have not mastered that trick.
  6. Free will/choice. Mechanisms are either under direct human control, are programmed to do certain things, or perform in a regular pattern, such as a clock. Life forms, in their natural settings, are free and have their own purposes. There are some regular patterns — sleep cycles, mating seasons, winter migration. But the day-to-day movements and activities of life forms are largely unpredictable. They make spur-of-the-moment decisions on where to search for food, where to find shelter, whether to fight or flee from predators, and which mate is most acceptable. In fact, the issue of mate choice is one of the most intriguing illustrations of free will in life forms — there is evidence that species may select mates for beauty over actual fitness, and human egg cells even play a role in selecting which sperm cells will be allowed to penetrate them.
  7. Able to gather energy from its environment. Mechanisms require energy to work, and they acquire such energy from wound springs or weights (in clocks), electrical outlets, batteries, or fuel. These sources of energy are provided by humans in one way or another. But life forms are forced to acquire energy on their own, and even the most primitive life forms mastered this feat billions of years ago. Plants get their energy from the sun, and animals get their energy from plants or other animals. It’s true that some mechanisms, such as space probes, can operate on their own for many years while drawing energy from solar panels. But these panels were invented and produced by humans, not by mechanisms.
  8. Self-organizing. Mechanisms are built, but life forms are self-organizing. Small components join other small components, forming a larger organization; this larger organization gathers together more components. There is a gradual growth and differentiation of functions — digestion, breathing, brain and nervous system, mobility, immune function. Now this process is very, very slow: evolution takes place over hundreds of millions of years. But mechanisms are not capable of self-organization. 
  9. Capacity for healing and self-repair. When mechanisms are broken, or not working at full potential, a human being intervenes to fix the mechanism. When organisms are injured or infected, they can self-repair by initiating multiple processes, either simultaneously or in stages: immune cells fight invaders; blood cells clot in open wounds to stop bleeding; dead tissues and cells are removed by other cells; and growth hormones are released to begin the process of building new tissue. As healing nears completion, cells originally sent to repair the wound are removed or modified. Now self-repair is not always adequate, and organisms die all the time from injury or infection. But they would die much sooner, and probably a species would not persist at all, without the means of self-repair. Even the existing medications and surgery that modern science has developed largely work with and supplement the body’s healing capacities — after all, surgery would be unlikely to work in most cases without the body’s means of self-repair after the surgeon completes cutting and sewing.

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The mechanism metaphor served a very useful purpose in the history of science, by spurring humanity to uncover the cause-and-effect patterns responsible for the motions of stars and planets and the biological functions of life. We can now send spacecraft to planets; we can create new chemicals to improve our lives; we now know that illness is the result of a breakdown in the relationship between the parts of a living organism; and we are getting better and better in figuring out which human parts need medication or repair, so that lifespans and general health can be extended.

But if we are seeking the broadest possible understanding of what life is, and not just the biological functions of life, we must abandon the mechanism metaphor as inadequate and even deceptive. I believe the mechanism metaphor misses several major characteristics of life:

  1. Change. Whether it is growth, reproduction, adaptation, diversification, or self-repair, life is characterized by change, by plasticity, flexibility, and malleability. 
  2. Self-Driven Progress. There is clearly an overall improvement in life forms over time. Changes in species may take place over millions or billions of years, but even so, the differences between a single-celled animal and contemporary multicellular creatures are astonishingly large. It is not just a question of “complexity,” but of capability. Mammals, reptiles, and birds have senses, mobility, and intelligence that single-celled creatures do not have.
  3. Autonomy and freedom. Although some scientists are inclined to think of living creatures, including humans, as “gene machines,” life forms can’t be easily analogized to pre-programmed machines. Certainly, life forms have goals that they pursue — but the pursuit of these goals in an often hostile environment requires numerous spur-of-the-moment decisions that do not lead to the predictable outcomes we expect of mechanisms.

Robert Pirsig, author of Zen and the Art of Motorcycle Maintenance, argues in Lila that the fundamental nature of life is its ability to move away from mechanistic patterns, and science has overlooked this fact because scientists consider it their job to look for mechanisms:

Mechanisms are the enemy of life. The more static and unyielding the mechanisms are, the more life works to evade them or overcome them. The law of gravity, for example, is perhaps the most ruthlessly static pattern of order in the universe. So, correspondingly, there is no single living thing that does not thumb its nose at that law day in and day out. One could almost define life as the organized disobedience of the law of gravity. One could show that the degree to which an organism disobeys this law is a measure of its degree of evolution. Thus, while the simple protozoa just barely get around on their cilia, earthworms manage to control their distance and direction, birds fly into the sky, and man goes all the way to the moon. . . .  This would explain why patterns of life [in evolution] do not change solely in accord with causative ‘mechanisms’ or ‘programs’ or blind operations of physical laws. They do not just change valuelessly. They change in ways that evade, override and circumvent these laws. The patterns of life are constantly evolving in response to something ‘better’ than that which these laws have to offer. (Lila, 1991 hardcover edition, p. 143)

But if the “mechanism” metaphor is inadequate, what are some alternative conceptualizations and metaphors that can retain the previous advances of science while deepening our understanding and helping us make new discoveries? I will discuss this issue in the next post.

Next: Beyond the “Mechanism” Metaphor in Biology

 

What Does Science Explain? Part 4 – The Ends of the Universe

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Continuing my series of posts on “What Does Science Explain?” (parts 1, 2 , and 3 here), I wish today to discuss the role of teleological causation. Aristotle referred to teleology in his discussion of four causes as “final causation,” because it referred to the goals or ends of all things (the Greek word “telos” meaning “goal,” “purpose,” or “end.”) From a teleological viewpoint, an acorn grows into an oak tree, a bird takes flight, and a sculptor creates statues because these are the inherent and intended ends of the acorn, bird, and sculptor. Medieval metaphysics granted a large role for teleological causation in its view of the universe.

According to E.A. Burtt in The Metaphysics of Modern Science, the growth of modern science changed the idea of causation, focusing almost exclusively on efficient causation (objects impacting or affecting other objects). The idea of final (goal-oriented) causation was dismissed. And even though the early modern scientists such as Galileo and Newton believed in God, their notion of God was significantly different from the traditional medieval conception of God. Rather than seeing God as the Supreme Good, which continually draws all things to higher levels of being, early modern scientists reduced God to the First Efficient Cause, who merely started the mechanism of the universe and then let it run.

It was not unreasonable for early scientists to focus on efficient causation rather than final causation. It was often difficult to come up with testable hypotheses and workable predictive models by assuming long-term goals in nature. There was always a strong element of mystery about what the true ends of nature were and it was very difficult to pin down these alleged goals. Descartes believed in God, but also wrote that it was impossible to know what God’s goals were. For that reason, it is quite likely that science in its early stages needed to overcome medieval metaphysics in order to make its first great discoveries about nature. Focusing on efficient causation was simpler and apt to bring quicker results.

However, now that science has advanced over the centuries, it is worth revisiting the notion of teleological causation as a means of filling in gaps in our current understanding of nature. It is true that the concept of long-term goals for physical objects and forces often does not help very much in terms of developing useful, short-term predictive models. But final causation can help make sense of long-term patterns which may not be apparent when making observations over short periods of time. Processes that look purposeless and random in the short-term may actually be purposive in the long-term. We know that an acorn under the right conditions will eventually become an oak tree, because the process and the outcome of development can be observed within a reasonable period of time and that knowledge has been passed on to us. If our knowledge base began at zero and we came across an acorn for the first time, we would find it extremely difficult to predict the long-term future of that acorn merely by cutting it up and examining it under a microscope.

So, does the universe have long-term, goal-oriented patterns that may be hidden among the short-term realities of contingency and randomness? A number of physicists began to speculate that this was the case in the late twentieth century, when their research indicated that the physical forces and constants of the universe can exist in only a very narrow range of possibilities in order for life to be possible, or even for the universe to exist. Change in even one of the forces or constants could make life impossible or cause the universe to self-destruct in a short period of time. In this view, the evolution of the universe and of life on earth has been subject to a great deal of randomness, but the cosmic structure and conditions that made evolution possible are not at all random. As the physicist Freeman Dyson has noted:

It is true that we emerged in the universe by chance, but the idea of chance is itself only a cover for our ignorance. . . . The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense must have known that we were coming. (Disturbing the Universe, p. 250)

In what way did the universe “know we were coming?” Consider the fact that in the early universe after the Big Bang, the only elements that existed were the “light” elements hydrogen and helium, along with trace amounts of lithium and beryllium. A universe with only four elements would certainly be simple, but there would not be much to build upon. Life, at least as we know it, requires not just hydrogen but at a minimum carbon, oxygen, nitrogen, phosphorus, and sulfur. How did these and other heavier elements come into being? Stars produced them, through the process of fusion. In fact, stars have been referred to as the “factories” of heavy elements. Human beings today consist primarily of oxygen, followed by carbon, hydrogen, nitrogen, calcium, and phosphorous. Additional elements compose less than one percent of the human body, but even most of these elements are essential to human life. Without the elements produced earlier by stars we would not be here. It has been aptly said that human beings are made of “stardust.”

So why did stars create the heavier elements? After all, the universe could have gotten along quite well without additional elements. Was it random chance that created the heavy elements? Not really. Random chance plays a role in many natural events, but the creation of heavy elements in stars requires some precise conditions — it is not just a churning jumble of subatomic particles. The astronomer Fred Hoyle was the first scientist to study how stars made heavy elements, and he noted that the creation of heavy elements required very specific values in order for the process to work. When he concluded his research Hoyle remarked, “A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”

The creation of heavier elements by the stars does not necessarily mean that the universe intended specifically to create human beings, but it does seem to indicate that the universe somehow “knew” that heavy elements would be required to create higher forms of being, above and beyond the simple and primitive elements created by the Big Bang. In that sense, creating life is plausibly a long-term goal of the universe.

And what about life itself? Does it make sense to use teleology to study the behavior of life forms? Biologist Peter Corning has argued that while science has long pursued reductionist explanations of phenomena, it is impossible to really know biological systems without pursuing holistic explanations centered on the purposive behavior of organisms.

According to reductionism, all things can be explained by the parts that they are made of — human beings are made of tissues and organs, which are made of cells, which are made of chemical compounds, which are made of atoms, which are made of subatomic particles. In the view of many scientists, everything about human beings can in principle be explained by actions at the subatomic level. Peter Corning, however, argues that this conception is mistaken. Reductionism is necessary for partially explaining biological systems, but it is not sufficient. The reason for this is that the wholes are greater than the parts, and the behavior of wholes often has characteristics that are radically different from the parts that they are made of. For example, it would be dangerous to add pure hydrogen or oxygen to a fire, but when hydrogen atoms and oxygen atoms are combined in the right way — as H2O — one obtains a chemical compound that is quite useful for extinguishing fires. The characteristics of the molecule are different from the characteristics of the atoms in it. Likewise, at the subatomic level, particles may have no definite position in space and can even be said to exist in multiple places at once; but human beings only exist in one place at a time, despite the fact that human beings are made of subatomic particles. The behavior of the whole is different from the behavior of the parts. The transformation of properties that occurs when parts form new wholes is known as “emergence.”

Corning notes that when one incorporates analysis of wholes into theoretical explanation, there is goal-oriented “downward causation” as well as “upward causation.” For example, a bird seeks the goal of food and a favorable environment, so when it begins to get cold, that bird flies thousands of miles to a warmer location for the winter. The atoms that make up that bird obviously go along for the ride, but a scientist can’t use the properties of the atoms to predict the flight of these atoms; only by looking at the properties of the bird as a whole can a scientist predict what the atoms making up the bird are going to do. The bird as a whole doesn’t have complete control over the atoms composing its body, but it clearly has some control. Causation goes down as well as up. Likewise, neuropsychologist Roger Sperry has argued that human consciousness is a whole that influences the parts of the brain and body just as the parts of the brain and body influence the consciousness: “[W]e contend that conscious or mental phenomena are dynamic, emergent, pattern (or configurational) properties of the living brain in action . . . these emergent pattern properties in the brain have causal control potency. . . ” (“Mind, Brain, and Humanist Values,” Bulletin of the Atomic Scientists, Sept 1966) In Sperry’s view, the values created by the human mind influence human behavior as much as the atoms and chemicals in the human body and brain.

Science has traditionally viewed the evolution of the universe as upward causation only, with smaller parts joining into larger wholes as a result of the laws of nature and random chance. This view of causation is illustrated in the following diagram:

reductionism

But if we take seriously the notion of emergence and purposive action, we have a more complex picture, in which the laws of nature and random chance constrain purposive action and life forms, but do not entirely determine the actions of life forms — i.e., there is both upward and downward causation:

reductionism_and_holism

It is important to note that this new view of causation does not eliminate the laws of nature — it just sets limits on what the laws of nature can explain. Specifically, the laws of nature have their greatest predictive power when we are dealing with the simplest physical phenomena; the complex wholes that are formed by the evolutionary process are less predictable because they can to some extent work around the laws of nature by employing the new properties that emerge from the joining of parts. For example, it is relatively easy to predict the motion of objects in the solar system by using the laws of nature; it is not so easy to predict the motion of life forms because life forms have properties that go beyond the simple properties possessed by objects in the solar system. As Robert Pirsig notes in Lila, life can practically be defined by its ability to transcend or work around the static patterns of the laws of nature:

The law of gravity . . . is perhaps the most ruthlessly static pattern of order in the universe. So, correspondingly, there is no single living thing that does not thumb its nose at that law day in and day out. One could almost define life as the organized disobedience of the law of gravity. One could show that the degree to which an organism disobeys this law is a measure of its degree of evolution. Thus, while the single protozoa just barely get around on their cilia, earthworms manage to control their distance and direction, birds fly into the sky, and man goes all the way to the moon. (Lila (1991), p. 143.

Many scientists still resist the notion of teleological causation. But it could be argued that even scientists who vigorously deny that there is any purpose in the universe actually have an implicit teleology. Their teleology is simply the “laws of nature” themselves, and either the inner goal of all things is to follow those laws, or it is the goal of the laws to compel all things to follow their commands. Other implicit teleologies can be found in scientists’ assumptions that nature is inherently simple; that mathematics is the language of nature; or that all the particles and forces in the nature play some necessary role. According to physicist Paul Davies,

There is . . . an unstated but more or less universal feeling among physicists that everything that exists in nature must have a ‘place’ or a role as part of some wider scheme, that nature should not indulge in profligacy by manifesting gratuitous entities, that nature should not be arbitrary. Each facet of physical reality should link in with the others in a ‘natural’ and logical way. Thus, when the particle known as the muon was discovered in 1937, the physicist Isidor Rabi was astonished. ‘Who ordered that?’ he exclaimed. (Paul Davies, The Mind of God: The Scientific Basis for a Rational World, pp. 209-10.

Ultimately, however, one cannot fully discuss the goals or ends of the universe without exploring the notion of Ideal Forms — that is, a blueprint for all things to follow or aspire to. The subject of Ideal Forms will be discussed in my next post.