Writing in the Washington Post on Thursday, May 5, 2005, Peter Selvin said: “Alarmed by proposals to change how evolution is taught, scientists and teachers are mobilizing to fight back, asserting that educational standards are being threatened by what they consider a stealth campaign to return creationism to public schools.” He explained to his readers that “…intelligent design [creationism]…[is] a carefully marketed theory that challenges accepted understandings of Earth’s origins in favor of the idea that a creator played a guiding role.”
What is a theory? I recently asked this question of a relatively learned friend. He answered by comparing theory to fact, stating that a theory was a non-substantive explanation for a set of facts. As more facts become known, he said, theoretical explanations give way to factual ones. Ultimately, a theory may be vindicated – proved by fact; or partially vindicated – partially substantiated by fact, but also partially disproved; or overturned.
In one sense my friend is right. When a historian uses this word, one can assume he gives it my friend’s meaning. And when a poet uses the word. And a writer. Almost any non-scientist, in fact. On the other hand, when a scientist or engineer means what my friend defined, he uses the word “hypothesis” or “hypothetical.” When he uses the word “theory” or “theoretical,” however, he means something entirely different.
In scientific usage “theoretical” is the opposite of “empirical.” In measuring the speed of sound in sea water, for example, researchers frequently use an equation that consists of a long series of increasingly smaller functions of density, salinity, temperature, and pressure. This equation is the result of measuring the speed of sound in sea water under a very large number of differing situations, and then deriving the equation from these data. It is called an empirical equation.
Another approach to the same problem is to create a mathematical model of the ocean, and to derive an equation for the speed of sound that depends upon the mathematical structure of this model. This equation is called a theoretical equation.
Both equations are real. One is derived empirically, the other theoretically. Each is subject to error, and each is only as good as its ability to predict the actual speed of sound in any given situation. Ultimately, scientists attempt to replace empirical equations with theoretical ones, as they gain a deeper understanding.
Albert Einstein’s Theory of Relatively is a set of theoretical equations derived from a mathematical model of the universe. They explain many things in our daily lives: why transistors work, for example. Quantum Mechanics is another theory in physics. It explains why nuclear reactors work.
These theories are real and highly accurate, because they predict events with great precision. They are theoretical – and they are true.
When an individual applies the historian’s definition to the scientist’s use of “theory,” the result is confusion and misinformation. While the scientist distinguishes between model-derived and empirical solutions, the lay person believes he distinguishes between assumption and reality.
For the layman fact ultimately displaces theory; for the scientist, theory ultimately explains fact.
A case in point is the theory of biological evolution, probably one of the best established and most widely accepted scientific theories. Well intentioned people who don’t understand the meaning of the word “theory” have assumed that the theory of evolution is an unproved hypothesis. Many of these individuals object to evolution on religious grounds, and use their misunderstanding of the nature of a scientific theory to reject one of the most essential unifying concepts in biological science.
In an ideal world, a scientist collects data, and then creates a theoretical construct that explains their existence. Following this, the construct is tested by various means to establish its ability to hold up to reality. Over time, the original construct typically undergoes modification as additional data become known. Occasionally a construct has to be discarded and replaced with something else, because new data cannot be fit into the old framework.
A good example of this is the old phlogiston theory, wherein a substance called phlogiston was believed to be consumed when something burned. Researchers weighed an object before burning, and then again after burning. Since it seemed to weigh less after burning, obviously, something had been consumed: phlogiston. The English clergyman Joseph Priestly discovered that when he heated mercury in a jar, the jar became coated with a red substance. If he put a mouse into the jar after the red substance formed, the mouse died. When the red ash evaporated, a glowing splinter thrust into the jar would burst into flame, and a mouse would become hyperactive. When Priestly described his experiment to the French chemist Antoine Lavoisier, he immediately realized from his own experiments that Priestly had discovered a new substance which he called oxygen. Lavoisier had determined through careful measurements that substances that burned actually took on weight. He concluded that Priestly had discovered the substance that supplied that weight: oxygen. Consequently the phlogiston theory was discarded in favor of Priestly’s and Lavoisier’s new theory.
Philosophical (and religious) arguments typically go the other way. You start out with a construct (hypothesis) which you then attempt to verify with data. If the construct really does reflect the outside world, then the data will tend to verify the construct. Unfortunately, when the data are at variance with the construct, ideologues typically will either ignore the data or twist and modify them so that they fit. Only very rarely do they modify their construct to fit the data.
An example of one such modification was when the Roman Catholic Church finally accepted the long established scientific fact that the Sun, and not the Earth, was the center of the Solar System.
In today’s world, the confusion of the difference between “theory” and “hypothesis” by non scientific people has resulted in a schism separating fundamental Christianity from modern biological science. Simply stated, the fundamental Christian perspective currently considers the Biblical construct more important than the data. In effect, people holding this point of view have decided that the Biblical Old Testament “explanation” for how humans came to be is “absolutely” correct. Consequently, they are forced to modify their and the public’s perception of the overwhelming data that supports biological evolution as scientists currently understand it, replacing it with a construct they call “Creationism” or “Intelligent Design.”
“Intelligent Design” is a construct built from events told in the Old Testament. “Scientists” who “believe” in this construct attempt to collect data that appear to support it. Because the data that gave rise to biological evolution directly contradicts the essence of their Intelligent Design construct, these “scientists” are forced to reject all these overwhelming data. This – in turn – results in their campaign to prevent biological evolution from being taught in the public schools, or at least to have Intelligent Design taught as an equally likely alternative to biological evolution.
This is so very unfortunate, because they accomplish two things: (1) They convince honest people who do not have the background to understand the error in thinking about “theory” and “hypothesis;” and (2) they completely discredit themselves to the traditional scientific community, and thus further the schism that already separates fundamental Christian believers from things scientific.
From my point of view this is especially ironic, because there is absolutely no reason why a person cannot believe in the underlying precepts of Christianity and simultaneously accept the modern theory of evolution in its full-blown glory. The God in whom fundamental Christians so ardently believe could be the architect of biological evolution without impacting in any way the fundamentalist Christian concept of original sin and ultimate redemption.
All it really would take is for fundamental Christian believers to accept the data collected by the scientific community, and where it appears to contradict any particular aspect of their “construct,” simply modify the construct until it is once again in compliance with reality.
The “Church” has done this for centuries – there is no reason it and its many splinter groups cannot continue to do so today.