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The Domains of Science
and Human Preferences

No one has ever seen one species evolve into another, yet scientists who study the history of the earth and the nature of living organisms are convinced that they do, and creationists, who are almost never professional scientists, are equally convinced that they do not. This is more than an esoteric problem that befuddles philosophers because it has become an unacceptably disruptive matter in many public schools. When our civilization is so totally dependent on science and technology, it is important that the citizens who make the nation’s decisions have a deep understanding of the nature of science and the strengths and limitations of scientific evidence. The basic intellectual demands for so doing are not overwhelming.

Two worlds of the mind
Science deals with the things and processes of the natural world that are generally codified as biology, chemistry, physics, geology, and astronomy. Strictly speaking, it seeks not truth per se but concepts that can explain those natural things and processes by using what is already known of natural things and processes. These understandings must be based on data derived from observations and experiments and they must be confirmable by others. Alternatively, the purely human aspects of ourselves such as love, friendship, hate, pleasure, personal perferences, personal beliefs, ethics, and religion demand neither evidence nor proof.

Thus, we live in two worlds of the mind. One is the world of science and rational thought that was so dominant among intellectuals in the 18th century that it was called “The Age of Reason,” or “The Enlightenment.” Those intellectuals were deeply impressed with the ability of Newton and many others to provide explanations for the properties of light, mechanics, and the movements of the heavenly bodies. For many human beings, this was unsatisfactory due to the lack of attention paid to human hopes and desires. The pendulum swung, and more emphasis was devoted to the humanities. This emphasis on personal preferences gave us the romanticism of the 19th century–a swing from the rational end of the spectrum to the emotional.

No choice is necessary, because a full human life requires that the rational and the emotional coexist. The rational must dominate when one asks for reliable explanations of nature, the identification of and cure of diseases, superior agriculture, and the technology required for our civilization. Alternatively, the emotional or romantic mode is more personal, reflected in our wants and dreams.

The two modes come into conflict in the debate between evolution and creationism. Teachers struggle to clarify one concept based on confirmable evidence and the other based on personal preferences and beliefs. Why does this serious condition exist? It exists because different segments of society accept different criteria for evidence.

A devout creationist truly believes and requires no confirming data. This belief demands the acceptance of supernatural phenomena, that is, things and processes that do not occur in nature and are above and beyond natural explanations and laws.

The dominant trend in the patterns of thought in Western Civilization since the Middle Ages has been to abandon supernatural explanations and to seek rational ones for natural phenomena. The enormous advances in our understanding of how the human body works, treating diseases, building trains, aircraft, and automobiles, producing more bountiful and useful crops, and communicating more rapidly and efficiently with others throughout the world are based on rational thought and the use of scientific procedures that form the basis of invention. They provide human beings with enormous power, but we must remember that this power can be used for good or for evil. The glorious news is that this grand ability is totally controlled by human beings. We determine whether science and rational thought will be used to augment or decrease human welfare and happiness.

Best explanation available
Scientists accept evolution because, after a century and a half, it continues to explain the existing data and has yet to be replaced by a better theory. The fact that the evidence for biological evolution is overwhelming does not mean that a creationist cannot believe in a divine creation as described in Genesis. In the United States, everyone has a protected right to believe anything natural, supernatural, or based on human preference. A major problem ensues, however, when creationists try to prevent the teaching of evolution in the public schools. Students should hear an honest evaluation of what scientists who have spent their lives studying living and fossil organisms have concluded about the history of life over time. This means surveying the data and understanding the interpretation of the data, which has left the concept of evolution the best explanation so far available to explain the history of life over the eons of geological time.

The goal of all science is to formulate a statement, a concept, or a theory that accounts for all the existing data on a major topic and that can be expanded, modified, or negated on the basis of additional information. There are many cases where a concept has been validated so adequately that one can say it is “true beyond all reasonable doubt.” One of these is the concept of evolution, which has been greatly expanded beyond its mid-19th-century formulation. New fields such as genetics and molecular biology have provided valuable new insights, along with new data from the classical fields of paleontology, comparative anatomy, and embryology. For example, the observation that all living creatures have bodies composed of cells and that many of the same chemical reactions occur within the cells of different species can be understood as a consequence of the fact that the ancestor of all living species was a cell and that the basic cellular structure and its chemistry has been conserved to this day.

There are no observations that invalidate evolution as being the only useful scientific explanation available. Nevertheless, for individuals lacking a broad background in biology and geology, it is not easy to relate these observations to the conclusion that evolution is a useful theory and the only scientific explanation. Unfortunately, this is true for many conclusions in science. For example, few individuals today will maintain that night and day are the result of the sun rotating around the earth, as common sense seems to tell us and as was believed for so many centuries. Instead, the rotation of the earth on its axis gives us night and day. This is now accepted, yet very few well-educated persons will be able to provide the evidential basis that this is so. The same goes for the Big Bang and other new theories in modern cosmology. It means little to most of us if told that one of the critical bits of evidence for the Big Bang is that the spectral lines in light from distant stars show a shift toward red or that the temperature in deep space is little more than one degree on the Absolute Scale. When a well-educated nonscientist accepts that the Big Bang is highly probable, it will almost certainly be because he accepts not the evidence but what the cosmologist says about its significance.

Conflict here to stay
Now back to the question of science and creationism. Does it really matter if individuals believe in divine creation? People are free to believe anything they wish. As is the case with science, however, religion can be used for good or evil, and the choice depends on human will.

It is probable that the evolution/creationism conflict will be with us as long as the current K-12 curriculum characterizes our schools. A solution will require an understanding of the basis of the disagreements between scientists and creationists. We must realize what scientists mean by confirmable scientific evidence and how it differs from other sorts of evidence. “Scientific” means that it relates to the things and processes of the natural world. “Confirmable” means that the scientific observations must be repeatable by others and the same results obtained. This excludes all supernatural statements that lack the key requirement of repeatability.

The majority of adults lack this understanding of the total incompatibility between what the scientists and creationists have to say. A final answer may come when the educational system changes to provide much better science education in the K-12 curriculum and especially in K-5. To the extent that ignorance is the problem, education is the solution.

The world today has become so complex and uncertain that plans for the present, and especially for the future, must be made on the best available evidence, not on supernatural dreams. For example, the world cannot support an infinite number of human beings, and even today we are exceeding the carrying capacity of nature to supply some of the necessities for life. There can be no ex deus machina to save our skins. It is essential for us to use the rational procedures of science to shape our future. Yet science alone will not ensure an acceptable continuation of the human experiment. Science and religion are both human constructs, and our responses to them can be no more than human choices. The future we choose will be an ethical decision, but the voyage toward it must be based on scientific procedures. Both a scientific head and a warm heart are needed–the heart to define the goal and the head to manage the journey.

John A. Moore is emeritus professor of biology at the University of California, Riverside, and the original supervisor of one of BSCS’s first three high school textbooks, Biological Science: An Inquiry into Life (BSCS Yellow Version). His newest book is From Genesis to Genetics: The Case of Evolution and Creationism (University of California Press, 2002).