Page:The Scientific Monthly vol. 3.djvu/15

 THE EVOLUTION OF LIFE 9

Although the motions giving riae to radiation are haphazard, the resulting forms of radiation which we observe are definite and beautifully arranged as if they proeeeded from perfectly coordinated and not from perfectly haphazard motions.

It is obvious that the answer to these questions put by a physicist may be reached in biology through observation.

Campbell has described the orderly development of the stars and Chamberlin the orderly development of the earth: is there also an orderly development of life? Are life forms, like celestial forms, the result of law or are they the result of chance? Thia is perhaps the very oldest biologic question that has entered the human mind, and it is one on which the widest difference of opinion exists even to-day.

Chance has been the opinion held by a great line of philosophers from Democritus and Empedocles to Darwin, and including Poulton, de Vries, Bateson, and many others of our own day : chance is the very eesence of the Darwinian selection hypothesis of evolution. William James' and many other eminent philosophers have adopted the ^' chance ^^ view as if it had been actually demonstrated, instead of being, as it is, one of the string of hypotheses upon which Darwin hung his theory of the origin of adaptations and of species. To quote the opinion of a recent writer:

And why not? Nature has always preferred to work by the hit or miss methods of chance. In biological evolution millions of variations have been produced that one useful one might occur.*

I have long maintained that this opinion is a biological dogma^® which has gained credence through constant reiteration, for I do not know that it has ever been demonstrated through the actual observa- tion of any evolutionary series.

Load has been the opinion of another school of natural philosophers, headed by Aristotle, the opponent of Democritus and Empedocles. This opinion has fewer philosophical and scientific adherents ; yet Eucken,*^ following Schopenhauer, has recently expressed it as follows :

From the very beginning the predominant philosophical tendency has been against the idea that all the forms we see around us have come into existence solely through an accumulation of accidental individual variations, by the mere blind concurrence of these variations and their actual survival, without the operation of any inner law. Natural science, too, has more and more demon- strated its inadequacy.

Unlike our first question as to whether the principle of life intro- duced something new in the cosmos, a question which is still in the stage of pure speculation, this fourth question of law versus chance in the

8 James, William, 1902, pp. 437-439.

• Davies, G. B., 1916, p. 583.

10 Biology like theology has its dogmas. Leaders have their disciples and blind followers. All great truths, like Darwin's law of selection, acquire a momentum which sustains half-truths and pure dogmas.

II Eueken, Budolf, 1912, p. 257.

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