The great revival of four centuries ago in art, in learning, in religion, reached also to science. At last the spell of ignorance, of unreasoning prejudice, of offensive dogmatism, and of vague mysticism, that had held the world for so long, was broken. The new life of science was feeble at first, and remained long in its swaddling clothes. It was about the middle of the sixteenth century that Copernicus gave his great work to the world; then no great work again for nearly one hundred years, when Kepler, Galileo, and Stevinus arise. But the century has not been an idle one. Everywhere men have been awakening to the new light, have begun to think freely and fearlessly; are no longer deterred by the cry of magic or the prohibition of church dignitaries from investigating into Nature for themselves. And so, when in the seventeenth century those mighty ones appeared, thoughtful people in great numbers were found to welcome the new truths; and at almost the same time Descartes by his essay on Scientific Method, and Bacon by the Novum Organum, were able to give an impetus to scientific investigation such as the world had never felt before.
The history of the progress of science from that time to this is too complex to receive any treatment in a paper of this character. How it has been throughout a record of successive triumphs; how gradually one department after another of Nature's workings has been mastered and reduced to orderly system; how all systems have been themselves reduced to one, harmonious and complete, in the magnificent generalization of evolution; how all the time not only has the sum of knowledge been steadily augmented, but the power of acquiring knowledge marvelously enlarged—all of that we know. That which has accomplished such results is science, and the process employed has been scientific method. We are in a position now to have a fairly intelligent idea of it. Look at it and see.
"Scientific method" is not, of course, a technical expression, as are induction, deduction, etc. Yet it means something very definite. It is that method of dealing with phenomena which reason declares and experience has shown to insure the greatest accuracy in results. There are in the complete process four necessary steps: 1. Observation of facts. 2. Comparison and classification, or generalization. 3. Deduction. 4. Verification.
We can see these steps alike in the simplest scientific attempt of our remote ancestors, and in the work of a Newton or a Darwin.
To use an illustration of the former suggested by the book of Leviticus. In very early times it was noticed that animals that had both the characteristics of being cloven-hoofed and of chewing the cud were good for food. A new animal is discovered having those characteristics. It is argued from the general principle laid down that this new animal is good for food, and the matter is verified by experiment. There are the four distinct steps: observation of the facts, drawing a principle from the comparison of the facts, deducing as to the particular case, verifying. The result is, of course, not only a classifying of the particular case, but also the extension of the principle. So with the generalization of the law of gravitation. Numberless facts were observed with the greatest care; from them the principle was generalized; from that again deductions were made as to particular cases; and the results were verified. But though the steps of the process are the same in both instances, yet what a vast difference between them! Take the first step, the observation of facts. All that the thought of the earlier age could do was to note a few striking resemblances and differences among the animals that roamed the neighboring forests. What could be done in the later age, ay, what the scientific temper of the age demanded, was the most rigidly careful examination of multitudes of facts; examination by a trained mind and with all the improved appliances which science and art had given to the world, and then submitted to the searching scrutiny of other trained minds, with like appliances. Or take the last step, verification. In one case it meant finding the effect upon the taste and upon the health. In the other, what it meant may be judged from the account we have of one of Newton's investigations. In applying his hypothesis of gravitation (it was only a hypothesis then) to the motion of the moon, there was a very slight divergence, about two feet a minute, between the time of the revolution of the moon in its orbit, as he calculated it and as he observed it. He was not satisfied until, eighteen years after, on account of an improvement made in the method of taking observations, he was able to obtain what he regarded as a verification.
And so what we learn from the history of science is the gradual development of scientific method. Scientific method in the work of Hipparchus meant a very different thing from the scientific method of the Chaldeans. Very different still is the scientific method of studying the heavens to-day. So to an even greater degree is there a difference between the scientific method of studying the earth to-day and as our fathers studied it. It is not merely the multitude of facts that we have learned, nor the marvelous instruments that we have made to aid us in our observations; it is also, and by no means least, this—that men all these centuries have been learning to observe, to reason, and to verify.
We may say that science and scientific method have grown and developed together: the development of one has invariably advanced the development of the other, and, on the other hand, where one has remained stationary, or has retrograded, so has the other.
History has enabled us to see this other fact also: that the conditions which interfered with the growth of science in the past not only interfere with it always, wherever they exist, but to very much the same degree interfere with the free application of scientific method. What those conditions were during one long period of history we saw—a failure to realize its importance as compared with questions of conduct; a tendency to comment rather than investigate; a tendency to ascribe everything to spiritual agency rather than to natural causes; and lastly, dogmatism. We very well know how, as a matter of fact, those very conditions do interfere with the application of scientific method to-day.
How far is scientific method applicable to the investigation of the Bible? Is there any department of human knowledge to which scientific method of investigation is not applicable? If scientific method is what we defined it to be, that method of dealing with phenomena which reason declares and experience has shown to insure the greatest accuracy in results, then there is obviously no department of knowledge to which that method is not applicable, for it means simply the method which will bring us nearest to the truth. When we are dealing with the highest spiritual verities we use that method which will bring us nearest to the truth; we are bound to use it in the interest of truth! That does not mean that we are to look for material causes for spiritual phenomena; nor does it mean that those things which in their nature appeal to the sensibilities, or have to do with conduct, or require an exercise of faith, must, in order for us to find out the truth, be removed from the domain of sensibility, conduct, faith. That would be a most unscientific method of investigation. The very first canon of scientific method is that it be appropriate to the matter in hand. And so in investigating the truths which are distinctly taught in the Bible—truths which are of the nature of a revelation of God's will and which are designed to reach and affect the whole nature of man—to take no account of other faculties in a man besides his power of apprehending intellectually, and of reasoning logically, would be unscientific beyond hope of pardon.