THE PROBLEM OF LIFE.--The problem is: What is it in an organism which causes it to behave in a fashion so impossible for any machine? To answer this question satisfactorily would be to have solved the mystery of life. Biologists do not answer the question; they do not say what this peculiar potency is, but they give it a name. Driesch calls it _entelechy_, i.e. "purposiveness," and he also speaks of _psychoids_, i.e. "primitive minds." Names do not carry us very far; but the mere fact that biologists have gone to the trouble of providing a name, is important. It constitutes an admission on their part that there is something mysterious about the organism; for it has been a principle of modern science since the days of Galileo never to appeal to mysterious causes if known ones can be found. The _deus ex machina_ method seems to them fundamentally unsound, and so it is. If every difficulty were considered solved merely by the word "mystery," knowledge would never advance. Labelled ignorance is still ignorance. It is not names, but things that are important. But in this particular instance the application of the name _entelechy_ indicates that, in the opinion of such an authority as Driesch, at any rate, something exists which no merely physical or chemical term can completely describe. And Driesch is typical of the trend of much modern biology. It is only the very extreme optimists who now look for a final explanation of the living organism in terms of physics and chemistry. RESULTS OF THE NEW BIOLOGY.--But if life resists all attempts to reduce it to matter and motion, we are confronted with the breakdown of the mechanical theory of the universe, which has been slowly but progressively elaborated since the days of Leonardo da Vinci, and applied impartially to the organic and the inorganic spheres. But this ultra-dogmatic theory now seems too cramped to contain the facts; even scientists resent the claims of materialist-mechanical orthodoxy. Some indeed adopt not merely a critical, but a provocative attitude, and seek to discredit the prestige of mechanics. Professor J. S. Haldane not only vindicates the freedom, but prophesies the speedy advance of biology to a position of pre-eminence. Not only are biological phenomena irreducible to terms of mechanics, but it is mechanics that will have to be re-interpreted in terms of biology. "It is at least evident that the extension of biological conceptions to the whole of nature may be much nearer than seemed conceivable even a few years ago. When the day of that extension comes, the physical and chemical world as we now conceive it--the world of atoms and energy--will be recognised as nothing but an appearance ... it will stand confessed as a world of abstractions like that of the pure mathematicians."[74]