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How the Whole Becomes More Than the Sum of The Parts

1971; Johns Hopkins University Press; Volume: 14; Issue: 3 Linguagem: Inglês

10.1353/pbm.1971.0030

1529-8795

H. A. Krebs,

Origins and Evolution of Life

HOW THE WHOLE BECOMES MORE THAN THE SUM OF THE PARTS* H. A. KREBSi A dinner lecture before scientists is an unusual occasion which warrants an unusual choice of topic, different in type from the several thousand papers presented at the ordinary sessions ofthe International Congress. It is this thought that prompts me to reflect, on this occasion, on a general biological question. This concerns the impact ofrecent biological progress on our concepts ofthe organization ofliving matter. I have in mind especially the fact that a living organism is a coordinated whole and the question to what extent this wholeness can be explained on a purely rational— as opposed to ideological—basis. This is ofcourse an old problem, but I believe that it now appears in a new light. Claude Bernard's Comments on the Wholeness ofLiving Organisms It was Claude Bernard who in 1865 first formulated theproblem clearly. In his Introduction to the Study ofExperimental Medicine [1] he discussed certain differences between a living body and the nonliving world and between the biological and the exact sciences. He argued that the objects and principles ofexperimental research in biology and in the exact sciences are identical, because the laws ofnature, that is, the relation between cause and effect, are the same in living matter and in the physical world. The only difference, he said, is in the degree ofcomplexity, which is much greater in living systems [1, pp. 111-117].1 But, Bernard pointed out, there is one special feature in the makeup of living organisms. This is the interdependence of the parts of the living body and the fact that living beings * Dinner lecture given on August 27, 1968, during the 24th International Physiological Congress at Washington, D.C. t Metabolic Research Laboratory, Nuffield Department ofClinical Medicine, RadclifFe Infirmary, Oxford, England. 1 Page numbers quoted throughout for [1] refer to the original French edition. 448 H. A. Krebs · Organization ofLiving Matter Perspectives in Biology and Medicine · Spring 1971 must be considered as being a "harmonious whole" ("ensemble harmonique "), asheput it [i, p. 150]. If, he said, weneglected thephysiological point ofview in the study ofvital function—that is, the wholeness of the organism—we may be led, even ifwe experimented skillfully, to very false ideas and very erroneous deductions [1, p. 150]. I would like to quote a few passages in translation. Physiologists are inclined to acknowledge in living organisms the existence ofa harmonious and pre-established unity where all components are interdependent and influence each other. We must appreciate that when we break up an organism by taking the different components apart it is only for the sake ofconvenient experimentation and by no means because we consider them as separate entities. Indeed when we wish to ascribe to a physiological property its significance we must always refer it to the whole organism and draw any conclusions only in relation to the effect ofthis property on the organism as a whole. [1, p. 154] Another passage states: Physiologists and physicians must always consider, at one and the same time, organisms as a whole and in their details without ever losing sight ofthe special circumstances ofall the characteristics which constitute the individual. [1, p. 158] After Bernard, other physiologists and philosophers, especially J. S. Haldane [2] and Smuts [3], have emphasized and discussed the quality of wholeness in living bodies, with special reference to teleological thinking. However, I will not enter discussions into these philosophical justifications ofteleology. Instead I want to point out that progress made in the course of the last ten years has transferred the treatment of the concept of the nature of the wholeness from the realm of philosophy and theory of knowledge to that of biochemical and physiological experimentation, from logical argumentation to experimental tests. Feedback Mechanisms as the Instruments of Wholeness The area which has provided important relevant information is that of enzymology, and in particular the study of the regulation ofenzyme activity . There are features in the behavior ofenzymes which directly bear on the phenomenon ofwholeness. The activity ofmany enzymes depends in a special way on other enzymes, and this interdependence is now known to be due to thefact that enzymes arenot merely catalysts ofextraordinary...