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Second Meeting: 6th June, 1910.
Dr. R. Briffault, President, in the chair.
New Member.—R. J. Morgan.
The President delivered the anniversary address, taking as his subject “The Nature of Life.”
The lecturer explained the mechanical theory of life, and contrasted it with the old theory of vitalism. The latter was, he said, inconsistent with the principle of the conservation of energy, and of the equivalence of forces. It was noteworthy, nevertheless, that in many quarters dissatisfaction had of late been expressed with the mechanical theory, and that many biologists displayed a tendency to return to vitalism in some modified form. Among the causes of this tendency were the fact that the mechanical theory did not supply an interpretation of the distinction between living and non-living matter, and that the ideal of the theory—the reduction of living processes to terms of physics and chemistry—had not in any instance been achieved. The mechanical theory originally regarded life as the property of a chemical compound, protoplasm. That view, however, was negatived by the fact that perpetual change of chemical composition is a
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sine qua non condition of life. The study of metabolic processes had recently made great advances, which were discussed at some length, and the lecturer concluded that nothing exactly analogous to the process was known in the inorganic world. Metabolism, which might be a manifestation, or cause, or result of unknown physical conditions, was, the lecturer submitted, the proximate known physical basis of vital processes.
Passing to a discussion of the reactions of living objects, the distinctive characters of those reactions appeared to be a continual self-adjustment, and readjustment to external conditions—in other words, adaptability. The analogy between automatic devices designed to meet a certain purpose, and adaptive response to all conditions, with continual readjustment, was, the lecturer said, superficial and misleading.
Since the physical conditions of the metabolizing organism differed in a fundamental manner from any to be found in non-living objects, it was not surprising that the principle of the self-adjusting mechanism could not be deduced from inorganic phenomena. And, since the readjustment was known in some cases to be accompanied by sensibility, it was not unreasonable to suppose that the physical phenomena corresponding to sensibility constituted that self-adjusting mechanism which is distinctive of living organization.