Page:Popular Science Monthly Volume 80.djvu/9



HE reader is aware that two conflicting conceptions are held in regard to the nature of life, namely, a vitalistic and a mechanistic. The vitalists deny the possibility of a complete explanation of life in terms of physics and chemistry. The mechanists proceed as though a complete and unequivocal physico-chemical analysis of life were the attainable goal of biology. It should also be stated that whenever a vitalist desires to make a contribution to science which is more substantial and lasting than mere argument or metaphor, he forgets or lays aside his vitalism and proceeds on the premises and methods of the mechanist. It is thus obvious that as far as the progress of biology is concerned the difference of viewpoint between vitalists and mechanists is of no consequence.

The difference between the two opposite views becomes only of importance when the results of biology are applied to ethical and sociological problems. Since applications of this kind present themselves constantly, the biologist may be pardoned if he raises the question whether or not our present state of knowledge justifies the expectation that life phenomena may ultimately be completely explained in terms of physics and chemistry. I intend to put before you a brief survey of some results, in the main recent, of scientific inquiry which I think may be utilized for an answer to this question.

Before going into these data, it may be necessary to allude briefly to a not uncommon misapprehension in regard to the nature of biological "truth" and methods. It is seemingly often taken for granted