Neuroscience and the Reductionist Temptation

This article was originally published in my column at the Colson Center. It is republished here with permission. For a complete directory of all my Colson Center articles, click here.

What a Thing is

In C.S. Lewis’s book The Voyage of the Dawn Treader, there is a fascinating dialogue that happens after the company from Narnia voyage to an island at the beginning of the end of the world. The Narnians meet a star named Ramandu, who dwells on the island with his beautiful daughter.

When the company are told that Ramandu is “a retired star”, Edmund announces, “In our world a star is a huge ball of flaming gas.”

Ramandu replies: “Even in your world, my son, that is not what a star is but only what it is made of.”

That’s an important distinction. What a thing is made of is not always the same as what a thing actually is.

The Brain-Plasticity Revolution

I thought of The Voyage of the Dawn Treader last week when I came across an intriguing article by Dr. Michael Merzenich, one of the leading pioneers in the burgeoning field of neuroplasticity.

Neuroplasticity is the science dealing with the flexibility of brain structures, based on the now proven understanding that changes in behavior and environment actually alter the neuro-circuitry of the brains. The understanding of brain plasticity has replaced the formerly-held position that the brain is a static and unchangeable organ.

In his bestselling book The Brain that Changes Itself, Dr. Norman Doidge showed that recent advances in the science of brain plasticity have enormous implications for treating learning disabilities, helping victims of strokes recover function and creating treatments for a number of pathologies. Brain plasticity also promises to help us achieve greater understanding about human emotion, as well as giving us insight into the reciprocal relationship between our choices and feelings. (For more information about brain plasticity, see Graham Taylor’s articles, “From Localizationism To Neuroplasticity” and ‘The Adaptive Brain.’)

The exciting thing about neuroplasticity is that scientists have only just begun to scratch the surface, yet already it has led to some paradigm shifts in our understanding of the human being.

Another reason why neuroplasticity is so exciting is because it is undermining many long-standing Darwinian assumptions about how the brain develops, as I showed in my Salvo Magazine article ‘The Neuro Transformers: Culture & the Malleability of the Human Brain.

The Materialist Fallacy

Paradigm-shifting scientific discoveries will always create new temptations for those with a materialistic worldview. As scientists are able to understand brain-processes better than ever before, it can be tempting for them to think they have finally understood what a human being actually is, not merely what a human being is made of. It can also create a temptation to explain human nature in ways that completely bypass spiritual properties which cannot be quantified or measured.

I was reminded of this temptation when I read Dr. Michael Merzenich’s article, ‘The Brain Plasticity Revolution’, based on a lecture given at the University of Konstanz in Germany.

Much of which we know now about brain plasticity is thanks to Dr. Merzenich, who I believe will eventually be recognized as one of the most important scientists of our era, if not all time. Because of this, it is with a little trepidation that I venture to challenge such a brilliant thinker. Yet Merzenich has fallen prey to the type of materialist reductionism that conflates what a thing is made of with what a thing actually is.

In his lecture, Dr. Merzenich excitedly shared that “Contemporary neuroscience is revealing, for the first time in our history, our true human natures.” He went on to state that we can stop asking the types of questions about human nature which have long occupied philosophers and priests. While it is nothing new for a scientist to claim that science can replace both religion and philosophy, the new science of brain plasticity has seemingly provided new ammunition to those who wish to make this extraordinary claim. Merzenich continued:

“Human wisepersons and societies have had great fun pondering about the mysteries of the origins of the ‘self’ — that unique, often, conscious embodied ‘person’ that is you, or me (or her or him). Philosophers and psychologists and anthropologists and shamans and gurus and priests and sages and physicians numbering in the thousands or millions in every generation of our species for nearly a hundred thousand years have struggled to understand the fundamental nature of we humans: the origin of that embodied ‘self’…”

“We now have first-level scientific answers to these questions. We now understand the basic processes that underlie the genesis of the ‘self’… (Emphasis his)

“For the first time in our history, IT (this modern science) DEFINES US.” (Emphasis his)

“That is another way of saying that we can stop arguing about WHAT we are. We know.”

I can’t help but think that Dr. Merzenich has overstated his case. There is no question that contemporary neuroscience has certainly made huge strides in understanding the processes that go into making our brains, personalities and emotions what they are. But to claim that brain science can define our very nature, and that the recent discoveries about brain plasticity have finally laid to rest all philosophical and religious questions about the self, is a non sequitur of enormous proportions. It would be like me saying that we can understand the nature of the soul from examining the body, or that we can fully define the mind because we know what happens in the brain, or that we can define the nature of love merely because we understand what happens chemically, physiologically and neurologically when a husband and wife have sex.

At root, Dr. Merzenich is committing the same category mistake made by Edmund in the opening dialogue, since it fails to distinguish between material and final causes (to use Aristotle’s nomenclature of causality). It is also a fallacy of composition because it assumes that what is true of the parts is true of the whole.

I do believe that we can understand the brain better now than ever before. But this does not mean that the science of brain plasticity defines us, or that it has replaced religion in providing answers about human nature.

Reductionism In History

Throughout the history of the modern world, a recurring temptation among scientists and psychologists has been to posit reductionist explanations for of what it means to be human.

For example, in the early 20th century Freud had some remarkable insights about the unconscious, but Freudianism becomes reductionist precisely when these insights are taken to be an all-purpose explanation covering all of human behavior. There is more to being human than simply the unconscious.

In the mid 20th century, B. F. Skinner had some insights into the role our environment plays in conditioning human behavior. Skinner and his followers went wrong when they assumed (or acted as if) all human behavior could be explained in terms of environmental factors (a theory known as behaviorism). There is more to being human than simply behavior.

Throughout the mid 20th century to the present, the Christian counselor Jay Adams had some insights about the role confrontation can play in a counseling context. Where he and his followers went wrong was when they assumed this was the only way counseling should operate (a view known as “neuthetic counseling”, which I discuss here.) There is more to inner healing than the neo-behaviorism of the rigid neuthetic paradigm.

In the scientific realm, the temptation of reductionism has been equally pervasive. In the 17th century, new machine metaphors began to emerge for describing the world: the world began to be seen as a giant clock and God as the great watch-maker. Descartes compared the coming of the swallows in spring to clocks, while early English anatomists like William Harvey (1578–1657) described the heart as a pump (a metaphor that Descartes extended to both the brain and the human nervous system). All of this was well and fine until the “Enlightenment” period came along and men began to take these metaphors a little too seriously, assuming that all of reality could be explained in purely mechanistic terms.

When Isaac Newton (1642-1727) succeeded in explaining the laws of motion by which the universe operated, a number of thinkers assumed that all of reality could be explained by these laws and that Newton’s discoveries had somehow eliminated the need for the supernatural or human free will. (J.R. Lucas discusses this in his book The Freedom of the Will.)

The temptation of reductionism is now apparent in the realm of brain plasticity. The reason reductionism is so tempting is because brain plasticity touches almost every aspect of how we behave as human beings, as David Brooks showed in his fascinating book The Social Animal. The science of brain plasticity really does explain a lot, but there are non-material aspects of being human that it does not, and cannot, ever touch upon.

The Limitations of Science

Warnings about the limitations of science are more necessary now than ever before, as some thinkers are treating neuroscience almost like a new type of religion. One author who has fallen prey to this type of thinking is Sam Harris, author of The Moral Landscape. According to Harris, neuroscience holds the key to everything we need to know, not only about the brain, but about ethics, morality and human well-being. As Harris summarized his project in the opening chapter of his book:

“The underlying claim [which this book aims to refute] is that while science is the best authority on the workings of the physical universe, religion is the best authority on meaning, values, morality, and the good life. I hope to persuade you that this is not only untrue, it could not possibly be true. Meaning, values, morality, and the good life must relate to facts about the well-being of conscious creatures – and, in our case, must lawfully depend upon events in the world and upon states of the human brain.”

From there Harris goes on to explain some fascinating discoveries about the human brain. Where he goes wrong is when he uses these observations as the basis of a comprehensive theory of moral values. However, as I pointed out in my earlier review of Harris’ book, he can only achieve this by first subtly redefining goodness to mean human well-being and then reducing well-being to pleasure and finally reducing pleasure to brain-states that can be quantified and scientifically analysed. Under the hammer of Harris’s reductionism, everything about what a human being is, how a human being ought to behave, and what it is that gives our lives ultimate meaning and purpose, is subsumed in the neurons and synapses of our brain. Here are some quotations from Harris’ book which shows how far he is prepared to press this materialistic reductionism:

  •  “Values, therefore, translate into facts that can be scientifically understood…” (p. 1)
  • “The more we understand ourselves at the level of the brain, the more we will see that there are right and wrong answers to questions of human values.” (p. 2)
  • “…moral truth can be understood in the context of science.” (p. 2)
  • “There are facts to be understood about how thoughts and intentions arise in the human brain… We will see that facts of this sort exhaust what we can reasonably mean by terms like ‘good’ and ‘evil.’ (p. 4)
  •  “…I am arguing that science can, in principle, help us understand what we should do and should want – and, therefore, what other people should do and should want in order to live the best lives possible.” (p. 28)
  • “…science can resolve specific questions about morality and human values, even while our conception of ‘well-being’ evolves.” (p. 37)
  • “I believe that we will increasingly understand good and evil, right and wrong, in scientific terms, because moral concerns translate into facts about how our thoughts and behaviors affect the well-being of conscious creatures like ourselves.” (p. 62)

Because Harris reduces good and evil to chemical reactions in the brain, he thinks it is theoretically possible that scientists may one day be able to find a ‘cure’ for evil. For example, he imagines a pill that people can take with their meals that would make it impossible for them to do anything evil for the rest of the day.

Both Merzenich and Harris have failed to recognize the limits of science. Both thinkers focus on recent advances in neuroscience as if this has finally provided us with the Rosetta Stone to answering life’s most basic questions. However, the best neuroscience can do is to provide a glimpse into the ways in which human beings have been fearfully and wonderfully made by their Creator. Yet, as C.S. Lewis’s Ramandu right reminds us, what a thing is made of may be quite different to what a thing actually is.