Religion and Science from Galileo to Bergson

by J. C. Hardwick

Schwann was also responsible for initiating a number of minute physiological investigations which led to a far more intimate knowledge of the action of nerves and muscles, and interpreted these in mechanical terms. "Investigations which were carried on with all the resources of modern physics regarding the phenomena of animal movements, gradually substituted for the miracles of the 'vital forces' a molecular mechanism, complicated, indeed, and likely to baffle our efforts for a long time to come, but intelligible, nevertheless, as a mechanism."[33]

Subsequent researches, notably of Helmholtz (1821-1895) and Meyer, lent strong support to this interpretation. The conception of the conservation of energy (an important axiom of the mechanical theory) was successfully applied by them to the economy of organisms. The organism was found not to create energy, but only to contain remarkably efficient means of deriving it from materials absorbed as food. Thus animal warmth and the power of motion are originally "sunlight transformed in the organism of the plant," and afterwards appropriated by the animal. The power with which we move our limbs is as much the product of combustion as is the power of a steam engine, the only difference being that the organism is, of the two, the more efficient converter of energy.

The Mechanical Theory Substantiated.—Thus, whether biologists were considering the structure or the behaviour of organisms, they were arriving at the same conclusions. The structure was revealed as physical and chemical structure, and the behaviour as the resultant of familiar physical and chemical processes. Hence biology came to be regarded as a compartment of physics and chemistry, for life itself was nothing but a complex physical or chemical phenomenon. Life could thus be satisfactorily expressed in terms of matter and energy. The speculations of Descartes seemed to be established by experimental science.

The Final Obstacle.—The situation, already satisfactory to those whose hope it was to see the mechanical theory impregnably established, was marred, however, by one untoward circumstance. The phenomena of organic structure, growth, and behaviour having been reduced to order, and expressed in terms of physics and chemistry, certain important facts still resisted explanation, and stood out as a last stronghold of the older view.

The Origin of Species.—The existence of definite forms of animal and vegetable life, whose infinite variety and complexity was continually being increased by research[34]—still remained a mystery. How did these innumerable species naturally and automatically come into being? was the question that must be satisfactorily answered before the mechanical view could be held to cover all the facts.

The direction in which to look for a reply had been indicated by a number of thinkers. The French naturalist Buffon, the philosopher Kant, and the poet Goethe—besides other thinkers—had already in the eighteenth century familiarised the idea that species are not immutable, but that, by some means or other, new forms of life are derived from pre-existing ones. The conception had gained a firm foothold in England, where it was hospitably entertained by Mr. Herbert Spencer, and where it formed the staple of a book which caused a good deal of controversy in its day, and which is not yet forgotten.[35]

Lamarck.—The evolutionary idea, however, though attractive to philosophers, and even to men of science, was insufficient as an explanation of the origin of species so long as the processes of transformation remained obscure. Naturalists could not accept an hypothesis for which there seemed to be such imperfect evidence. An ingenious French scientist, J. Baptiste de Lamarck (1744-1829) had indeed, in 1809, propounded the theory—ever since known by his name—that the use or disuse of particular organs might, after a long series of generations, result in the formation of new species. (The ideas denoted by the words "environment," "adaptation," "acquired habits"—now so familiar—may be said to have been introduced by him). But the scientific prejudices of the time were against Lamarck's theories, and he had to lament their inhospitable reception. Indeed Lamarck's critics did not hesitate to exercise their powers of ridicule, or to make fun of the giraffe who derived his long neck from the attempts of his ancestors to browse on high trees. Darwin himself talks of "Lamarck's nonsense," and of his "veritable rubbish"—language, however, which he was subsequently able to retract.

The New Geology.—Perhaps the most stubborn obstacle which Lamarckian theories had to meet was the current prejudice as to the age (or youth) of the earth. Contemporary geologists were by no means prepared to grant Lamarck the illimitable periods of time which his transformation processes seemed to require. Consequently it is not surprising that the new theories, perhaps for the first time, received a measure of justice at the hands of one who himself became responsible for a revolution in the science of geology.

"I devoured Lamarck en voyage," writes Charles Lyell, describing a journey from Oxford in 1827. "His theories delighted me more than any novel I ever read, and much in the same way, for they address themselves to the imagination.... That the earth is quite as old as he supposes, has long been my creed."[36]

In spite of the fascination of these theories, however, Lyell was not carried away by them, and it was not for some years that he estimated them at their true value. Meanwhile the new geology made its appearance with the publication of the three volumes of his own Principles of Geology, between 1829 and 1833. The significance of the book for biological speculation—for theories of the origin of species—lay in its thesis that the present condition of the earth is the product of geological processes incalculably long. Hitherto the "catastrophic theory" had been dominant—the notion that a series of immense catastrophic events (like the Deluge) had been responsible for the present condition of the earth's surface. For this Lyell substituted his "Evolutionary Theory," according to which the almost invisibly slow geological processes which we may now see operating around us, are typical of the behaviour of the crust of this planet for incalculable periods of time; for even the slowest changes, if sufficient time is allowed them, are capable of producing the most stupendous results. Lyell may be said to have extended the age of the earth ad infinitum. Just as Galileo removed all barriers of space, Lyell removed those of time. Their joint achievement was to present to humanity a universe infinite both in space and time—a staggering conception.