Page:Popular Science Monthly Volume 73.djvu/545

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ASPECTS OF MODERN BIOLOGY
541

specialists were so segregated that they were scarcely or not aware of the fact. The grouping was sometimes according to classes, orders and families; sometimes according to physiological or morphological aspects of things; but everywhere it seemed that narrowness increased, and that broad conceptions of the Darwinian type were fading away.

The new attitude typified by Professor Bateson not only unifies the branches of zoology, but makes zoology and botany one. Greedy for the results of special research in every department, it yet makes all serve a common end. So far from despising or discouraging the most minute enquiries in limited fields, it gives them all a new purpose and new meaning, as contributory to the philosophy of life, which is, indeed, the sum of all philosophy. We find ourselves at that meeting point of monism and dualism, of synthesis and analysis, where the electric spark of human understanding always has had and always will have its birth.

Professor Forel, of Switzerland, in a recently issued book, has called attention to the difference between mathematical and ordinary reasoning, including in the latter the methods necessarily employed in the biological sciences. In mathematics, we start with certain postulated facts, and given definite methods of procedure, climb up a ladder of argument, each part of which is supported by the one below. An error at any point vitiates the whole piece of work; while, if there is no error, the result is said to be demonstrated beyond dispute. Systems of logic have been constructed in the same manner, and such processes have found great favor with lawyers and theologians whose main purpose has been to support theories rather than ascertain the truth.

In the natural sciences, as in the every-day affairs of life, the method is entirely different. Desiring to determine the state of things at any point in time or space, we converge upon it all the pertinent evidence we can secure, and form a judgment upon the collection. We do not profess to exclude the possibility of error; rarely do we feel so well supplied with facts that others are not welcome. Those of us who have worked long among biological facts have so often made mistakes, or discovered the mistakes of others, that we have become somewhat more humble-minded and less assertive than we used to be. This humility, however, is coupled with a keen sense of the tremendous weight of evidence in favor of certain conclusions. We do not assert that we must be right, but we at least demand an equivalent load on the other side of the scales before changing our opinion: a demand not readily comprehended by those to whom our body of facts is invisible.

In Colorado to-day we find existing many millions of individuals of animals and plants, presenting extreme diversities of form, color and size, and distributed in certain particular ways. It is the business of the naturalist to find out the how and why of all this, so far as he can.