One of the most universal of human traits is the need 'to understand the physical environment in which man finds himself. Sometimes the drive is a matter of comfort or survival; sometimes it is a deep, inborn curiosity. Whatever the immediate motivation, man derives a sense of certainty in his life by learning how nature operates.
Man's earliest records and artifacts give evidence of his search for assurance that crops will grow, that disasters will not come again, and that life will be long. Today the methods of discovering nature's secrets are different, as are the specific secrets we wish to discover, but like earlier man, we are still uncomfortable with uncertainty about sustenance or surroundings.
What kind of certainty can we achieve regarding the natural world? What sort of "proofs" are available for our interpretations and predictions, and how much confidence can we place in them?
What has frequently been called "the scientific method" is really nothing more than a formal application of an instinctive procedure we all use in everyday life. For example, walking into a city square, you notice a large group of people crowded together. Your curiosity causes you to check whether everyone is looking at the same spot. If they seem to be, you move closer, peering between heads and trying to spot the center of interest.
Notice the sequence of events. Observation of the crowd leads to the possibility of a common pattern. The pattern suggests further observation, resulting in more (or less) confidence in the pattern. The process continues until either your expectation is rewarded (by an interesting sight) or disproved (the people were just waiting for a bus).
Likewise, science begins with sensory observations of the events and environment around us—seeing, hearing, touching, tasting, and smelling. Modern science greatly extends the range of the human senses by precise instruments. Now we can see fainter light and smaller objects than ever before, measure distance and speed more accurately, ob serve faster and slower events, et cetera. It is still true, however, that knowledge of the natural world begins with what our senses record, even if it is the movement of a pointer or the electronic tracings on an oscilloscope.
Certain philosophies have insisted that this first step in finding certainty in nature is flawed, that we cannot be sure our "observations" are not just illusions manufactured by our mind. Such philosophers maintain that since one sense observation can be supported only by an other similar observation, the argument is circular. "True reality" then exists on some higher plane, such as the thought process (for the ancient Greeks) or a cosmic principle (for some Eastern religions).
Modern science and Western philosophy offer no disproof of this approach to reality other than the pragmatic view point that observation is all we have. We might as well continue to use it if it produces satisfactory results. The scientist in effect says, "I can't tell for sure whether the world I see is, in fact, real or simply an illusion, but I can continue to make sense out of my existence by building on the assumption that what I observe is real."
After the initial observations have been made, the resulting information must be organized into a pattern or theory. Without such a pattern, even a wealth of accurate observations is nothing more than a hopeless jumble of isolated facts, in which every sunset, tree, or insect is as unfamiliar and mystifying as the previous one. No understanding of the past or prediction of the future is possible without forming patterns and extending the meaning of our current observations backward and forward in time by applying the pattern.
We are so accustomed to this process of pattern recognition that we hardly notice we are doing it. We expect any event repeated two or three times to happen again in the same way unless it is very much out of the ordinary. Scientists find that one of the most remarkable characteristics of the human brain is its extensive capacity for pattern recognition. Modern computers have impressive capabilities for speed and accuracy, but even the largest are poor at pattern recognition compared with the brain of a small child.
Frequently an analogy or model helps us to find a pattern in a series of observations. When we say, "I understand," we often mean, "I see how this thing is like something more familiar." To show how gravity keeps the planets in orbit around the sun, we compare its action to that of a string holding a ball whirled in a circle. Nearly everyone has swung a weight on a string at one time or another, so the familiar situation is used as an analogy for the concept of gravity.
Of course, analogies are not expected to be perfect representations, or to "walk on all four legs," as someone has put it. The string represents gravity only in some respects. Obviously, we don't expect a thin, visible strand between the sun and earth. The visible string helps us understand the unfamiliar concept of a pull without visible means.
The lack of a suitable analogy often hampers the scientist. The brain continues to mystify scientists, for example, because no suitable electrical, chemical, or mechanical model can be found to help us understand its operation as a whole. In the realm of the atom and the nucleus, no single model has proved suitable, so scientists are forced to use various analogies to help them under stand different experimental results—wave properties for some results, and particle characteristics for others. Mathematics is a help to the natural scientist because it provides models of limitless accuracy unhampered by physical annoyances like friction and noise.
Once a pattern has been selected, we then apply it to new observations to produce predictions or interpretations. Once we associate loud, rumbling noises with danger, another loud, rumbling noise triggers the expectation of danger again.
Now we come to the crux of the matter: What right have we to trust in this process and how much certainty is there in the result? How much significance and value should we attach to a scientific prediction of a future event or an interpretation of the past?
For centuries scientists, philosophers, and mathematicians have searched for a way of proving that the method described above does, in fact, produce trustworthy and reliable results. What they have come up with instead is a conviction that there is no absolute certainty in the method. In other words, the accuracy of predictions or interpretations based on observations and pattern forming cannot be guaranteed.
Scientists expected something more solid from mathematicians and philosophers who have sought and found proofs for centuries. Scientists did not realize at first that there is a fundamental difference between proofs in mathematics and what is needed to justify the scientific method. A statement that an apple will fall to the ground is rather different from a statement that two triangles are equal.
The mathematician first lists his definitions and assumptions, spelling out very clearly what is meant by a line, an angle, a triangle, equality, et cetera. His proof then consists of using rules of logic (that everyone agrees on) to decide whether or not the conclusion follows from these assumptions. Mathematicians are convinced that such a proof is always possible, although it may be very difficult to find. The mathematician thus works within limits of his own choosing and does not trouble himself with considerations outside these limits.
The apple, on the other hand, is expected to fall because other objects with similar characteristics have been ob served to fall under similar conditions. In natural science, the nature of the problem demands that one start with the conclusions (observations) and then find the list of assumptions (the pattern or theory) that will account for these conclusions. The difficulty is that no matter how many observations one makes, there are always more to be made! One may observe a thousand times that a weight falls downward when released, but one can always make more observations tomorrow, next week, or next year.
Scientists now believe that they can expect a definite Yes or No to the question "Do all the observations made so far fit a certain pattern or set of assumptions?" Regardless of the answer, how ever, scientists are not guaranteed that the next observation they make will also fit the pattern.
"Proof" in natural science thus takes on a different meaning from the idea of a proof in mathematics. In a strict sense, nothing is ever proved by an experiment in natural science. The best that an experiment can do is to add to our confidence in a given pattern. A thousand experiments cannot prove an assumption, but a single experiment can dis prove it. (One gray cat disproves the thesis that "all cats are black.") How ever, continued experimentation is valuable, for if we have put a concept to a very severe test and have failed to dis credit it, we can attach greater importance to it. The more severe the test, the more our confidence grows when the concept succeeds.
If the scientific method is not guaranteed reliable, then why is it used at all? It continues partially because the alternative is to assume that there is no pattern in the natural world, that meaningful relationships are either completely absent or hidden from us. More significantly, the scientific method is kept because it produces useful results. What is missing is only the guarantee.
Records of observations reaching back hundreds of years provide strong evidence that nature does follow regular repeated patterns. There is not the slightest bit of proof (in the mathematical sense) that this is so, only a large quantity of evidence. The entire scientific edifice rests on this one proposition—the regularity and repeatability of natural patterns. This proposition, in turn, rests on trust, or, if you will, faith. No scientist now looks for proof of this assertion; it is so widely taken for granted that it is seldom mentioned.
Confidence in a scientific pattern grows with each success it has in giving order to observations of natural events. The greater the variety of events it can be applied to and the more people who successfully use it, the more trust is placed in it. Different words are used to indicate different levels of confidence. The pattern starts out as an "idea." If it meets with some success, it is regarded as a "hypothesis." As the trust grows, the concept may become a "theory." Only a few patterns that have broad application to many facts and that apply almost without exception become "laws." No matter how successful a pattern is, though, it is never entirely beyond question.
There are many ways in which a scientific prediction can go wrong. The scientist may not have been careful enough in making observations, possibly over looking some that were contrary; the wrong pattern may have been formed, either through ignorance or bias; or the pattern may be correct, but it may be applied incorrectly. Many examples of these problems can be found in the history of science.
The products of science are interpretations of the past and predictions of what is to come. The farther back or ahead we try to probe, the less certain our results become. It is possible to get some idea of the accuracy of a prediction by simply waiting to see whether it comes true (provided it refers to a time not too far distant). The irreversible march of time means that predictions far ahead and interpretations of the distant past can never be verified directly. Unless some new and overwhelming evidence is found, there is no way of checking such conclusions for accuracy.
Over the years, techniques have been developed in the exact sciences to reduce as much as possible the uncertainty of our concepts of nature. Wherever possible, instruments are used to make measurements and record them in order to reduce the chance of human bias. Experiments are repeated to reduce the likelihood of unusual coincidences. Careful records are kept to avoid depending on human memory. Logic and mathematics are used to help in the pat tern-finding process.
Most important of all, scientists have learned to recognize the importance of interactions between scientists. A single person is likely to have many blind spots and prejudices, but if others assist in the experiments or criticize the results, it is less likely all will have the same prejudices. The more successfully a concept can stand up to application and criticism, the more trust we can have in it.
While this interaction process is one of the strong points of science, it is by no means without flaws. All too frequently, criticisms are based not so much on the desire to test an idea as on personal feelings and fears, either consciously or unconsciously. Occasionally, a whole group of people working on the same problem do have the same blind spot, for years overlooking an explanation that seems so obvious later.
Imperfect as the method may be, however, it is the best that humans can do. Scientists make the utmost effort to maintain high standards of objectivity, trying to keep personal feelings out of scientific discussions and trying to be as honest as possible with themselves in ferreting out blind spots.
Wherein, then, lies the strength of scientific reasoning? To be perfectly candid, one would have to say that the strength comes from faith—faith that one has been honest in the process of forming concepts of how things work, and, last but not least, faith that the natural world is orderly and can be understood at least in part by the process of reason.
Is science at a disadvantage because it does not have a more solid foundation for its work? All disciplines and modes of thought ultimately rest on the same foundation of faith through experience. In interpersonal relations, for example, there is no rule we can apply to prove who will be trustworthy. We gain confidence in a person through experience; the more we share with a person and the greater the variety of shared experiences, the more our trust grows. We may have some guidelines by which to judge a person's trustworthiness, but those, too, have been developed through our own and others' experience.
Even our faith in God is developed through experience with Him. David said, "O taste and see that the Lord is good" (Ps. 34:8). Our trust grows as we draw on a wider and wider background of circumstances in which we have trusted and He has sustained us beyond all expectations.
Nature in itself gives us no clue why it should be so regular and dependable. One of the most famous scientists of our century, Albert Einstein, said, "The most incomprehensible thing about nature is that it is comprehensible."
It is in Christianity that we find the essential idea that makes possible the study of nature by observation and pat tern. Here we find a Creator God who made and upholds the entire universe. In the Scriptures, God reveals Himself as the source of everything in nature, both the material and the organization. Through His interactions with men He shows Himself to be trustworthy and dependable. With this background, it is reasonable to trust the regularity of nature and to try to comprehend it.
The very function of reason and choice given to man by the Creator depends on the presence of regularity. Without a relationship between cause and effect, "choice" would mean nothing more than the flip of a coin. Thus, faith in a regular and understandable universe is a fitting complement to faith in the God who created the world and commanded man to subdue and have dominion over it.
