Within Reason: Rationality and Human Behavior.

An eminent neurologist explores the role of reason in human evolution and daily consciousness, explaining how the mind works and offering a thoughful defense of the value of science and rationality. 12,500 first printing.

Introduction

When I was young, I was taught that education was important because without it we would be doomed to stupid behavior and opinions based upon prejudice. Educated people, I was told, were able to make wise decisions and to distinguish between right and wrong because they had the power of reason available to them. I grew up during the Second World War, and one of my most vivid childhood memories was a kaleidoscope of movie images shown in British schools in 1946, depicting the Nazi death camps. I was puzzled, for I had been led to believe that these atrocities were the irrational work of barbarians whose evil stemmed from ignorance. Yet I was also taught that Germany was distinguished by a history of outstanding reason, expressed in philosophy, music, poetry, science, and technology. If what I had been told about wisdom coming from education was true, how was it possible that Germany, the home of Bach, Beethoven, Brahms, Goethe, Leibniz, and Kant, could become a nation driven by hatred and complicit in the worst crimes against humanity that the world had ever seen? The conflict remained with me and gradually matured into a series of questions. Does reason direct what we do? If we think more, do we behave better? In short, could the nightmare of the Second World War have been avoided if the leaders of National Socialism had acquired, in some miraculous way, a sudden capacity for more reason?

Sadly, the facts do not support this. The intellectuals of Germany were among the first to embrace National Socialism. Wagner and Nietzsche blazed the trail in the nineteenth century, and by 1933 large numbers of university faculty were ready to champion National Socialist ideology. Other representatives of the educated classes, the lawyers and the physicians, and even more practical leaders, the industrialists, joined the throng. Many Europeans outside Germany looked on with approval. In some respects Hitler was expressing a widespread and influential sentiment that permeated the thinking of European intellectuals. The National Socialist movement was not conceived by ignorant people; its roots lay in the intelligentsia. It is difficult to escape the conclusion that if the leaders of National Socialism had achieved a dramatic increase in their capacity for reasoning in 1939, their regime would simply have pursued its policies with a more intelligent war machine; the goals would not have changed. National aggrandizement, territorial expansion, and institutionalized racism would have continued with more efficient weapons. The management of the "final solution of the Jewish question" was entirely dependent upon the ability to harness a product of reason -- modern technology -- to the problem of mass transportation, the safe manufacture and containment of Zyklon B, and the engineering of incinerators that could be fueled by the continuous ignition of melting human tissues.

Yet there was a paradox: vital resources were committed to the "final solution" though this diversion of manpower and material weakened the war effort. The German armies were in full retreat on all fronts. How can one make sense of this subversion of effort? The assembly of historical facts seems to amount to a grotesque concoction of reason with unreason. These events of my childhood kindled a deep personal curiosity about why people do things. The curiosity stayed with me, and as the war receded, my questions took a more general form. Have people all over the world been so irrational throughout history, and if so, why? I was assuming a natural tendency for us to be rational, but where is the evidence for this? I rephrased the questions into a more approachable form: What do we know about reason and the way we use it?

To pursue my curiosity, I began to look for information. Where possible, I have taken the position of a neurologist, because I happen to be a neurologist, but also because neurology gives a close-up view of some of nature's harshest but most illuminating experiments -- injuries that damage different parts of the brain. Strokes, tumors, and trauma may isolate and destroy one particular mental capacity, leaving everything else intact. Nature's disasters can thus help to explain how the brain works and shed some light on the instrument that stands at the center of the intellect: human reason.

I have taken to heart Francis Bacon's dictum that "truth emerges more readily from error than from confusion". Where evidence is indefinite, I have tried to find the most probable position, recognizing that it may ultimately prove to be wrong. My exploration has led me to a conclusion that was somewhat unexpected. Reason is a biological product -- a tool whose power is inherently and substantially restricted. It has improved how we do things; it has not changed why we do things. Reason has generated knowledge enabling us to fly around the world in less than two days. Yet we still travel for the same purposes that drove our ancient ancestors -- commerce, conquest, religion, romance, curiosity, or escape from overcrowding, poverty, and persecution.

To deny that reason has a role in setting our goals seems, at first, rather odd. A personal decision to go on a diet or take more exercise appears to be based upon reason. The same might be said for a government decision to raise taxes or sign a trade treaty. But reason is only contributing to the "how" portion of these decisions; the more fundamental "why" element, for all of these examples, is driven by instinctive self-preservation, emotional needs, and cultural attitudes. We are usually reluctant to admit the extent to which these forces govern our behavior, and accordingly we often recruit reason to explain and justify our actions. The transparency of our efforts is revealed by the term we have coined for covering up this irrational behavior: rationalization.
The rest of this chapter outlines some of the hopes for reason and some of the disappointments. In chapter 2 I develop a working definition of "reason." I deliberately avoid concentrating on any one aspect of reasoning, such as the psychological process of making decisions. If I pursued a narrow area in depth, I would thwart my attempt to view the whole picture of reason's place in human life, so in subsequent chapters I have included a wide range of topics, taking each "to only one decimal place" to keep the totality of rational behavior in perspective.

Since reason and language are so closely linked, I devote chapter 3 to delving into linguistics and the evidence that under exceptional circumstances neurological disease can separate reason from language. In chapter 4 I trace the development of social organization, for there is now a body of evidence suggesting that intelligence evolved from the need for individuals to cooperate in order to survive. In chapters 5 through 11, I follow the role of reason in the creation and maintenance of our most hallowed institutions: morality, commerce, government, religion, art, and science. In the remaining chapters I look at how reason operates in the human brain and mind.

Reason, like instinct and emotion, has evolved to facilitate the attainment of biological goals. Curiously, we have often found it easy to use reason in a harmful way. Chekhov's prophetic words, written a century ago, have a contemporary ring: "Man has been endowed with reason, with the power to create, so that he can add to what he's been given. But up to now he hasn't been a creator, only a destroyer. Forests keep disappearing, rivers dry up, wild life's become extinct, the climate's ruined, and the land grows poorer and uglier every day."

We proclaim that the disastrous events of the two world wars will not be repeated, but the same forces that led to those tragedies persist today, barely beneath the surface. Contemporary examples are, unfortunately, abundant: the death of 30 million Chinese as a result of political mismanagement committed under the ironic slogan of "The Great Leap Forward," the killing fields in Cambodia, the slaughter of Kurds in Iraq, the "ethnic cleansing" in Bosnia, and the tribal massacres in Rwanda. The list is long and continues to grow.

The evidence compels the conclusion that in spite of our capacity for reason, we remain tied to the motivation provided by our biological drives and cultural attitudes. In these circumstances I argue a humanist position informed, even guided, by recognition of the limits of reason. To place reason in perspective, we should take it down from the pedestal upon which expectations of supremacy have placed it. When we do this, we find that in many ways reason is like language, for both are highly complex instruments developed for biological purposes. They help us to achieve what we want, without having any real impact on why we decide what we want. Both operate unobtrusively; we take both for granted.
Hope and Disappointment

In the past, reason has been given the status of an independent, external and ultimate authority, with the ability to confer wisdom and goodness. Like a deity, reason was conceived as all-powerful. The ascent of reason began when the ancient Greeks surveyed the universe and attempted to sort out the confusion of ideas that had accumulated over previously known history. The Greeks were not the first to pay attention to reason, but they used it more extensively than anyone had before, raising rational discourse to an exalted status. Sophocles caught the spirit of his times in a single line: "Reason is god's crowning gift to man". Aristotle echoed this view a century later: "For man, therefore, the life according to reason is best and most pleasant, since reason more than anything else is man". In Rome, Cicero proclaimed that "reason is the ruler and queen of all things". Similar views were forming in India, and in China Confucius was on the same track.

This early optimism proved to be transient. After a few centuries of achie...