Review of This is Biology: The Science of the Living World, by Terry Ryan. Published by The Belknap Press of Harvard University Press. Cambridge, Massachusetts (1997).


Mayr, who Stephen Jay Gould describes as “the world’s greatest living evolutionary biologist” takes the reader through the history of biology, evolution and the philosophy of biology. He ends the book by sharing what he thinks this history should teach all of us: scientists and laymen alike. Below is a brief review of Mayr’s insights, as developed in This is Biology, that we think are relevant to the work of The 21st Century Learning Initiative.

Mechanism versus Vitalism equals Organicism

Mayr opens his book by providing the reader with a history of Western understandings about the natural world. He observed that the “Early beginnings of a natural (as opposed to supernatural) explanation of the world were made in the philosophies of various Greek thinkers, including Plato, Aristotle, Epicurus, and many others. These promising beginnings, however, were largely forgotten in later centuries. The Middle Ages were dominated by strict adherence to the teachings of the Scriptures, which attributed everything in nature to God and His laws. But medieval thinking, particularly in folklore, was also characterized by a belief in all sorts of occult forces. Eventually this animistic, magical thinking was reduced, if not eliminated, by a new way of looking at the world that was aptly called “the mechanization of the world picture.” (p. 3)

The mechanization of the world picture, Mayr argued, “Culminated in Descartes’s claim that all organisms except humans were nothing but machines…Descartes (1596-1650) became the spokesman for the Scientific Revolution, which, with its craving for precision and objectivity, could not accept vague ideas, immersed in metaphysics and the supernatural, such as souls of animals and plants.” (p.3) Mayr pointed out that he thought it strange that this world view could have had such a long-lasting popularity, (it was accepted well into the 20th century) when one considers “That no machine has ever built itself, replicated itself, programmed itself, or been able to procure its own energy.” However, “The success of Galileo, Kepler, and Newton in using mathematics to reinforce their explanations of the cosmos also contributed to the mechanization of the world picture. Galileo (1623) succinctly captured the prestige of mathematics in the Renaissance when he said that the book of nature ‘cannot be understood unless one first learns to comprehend the language and read the letters in which it is composed. It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures without which it is humanly impossible to understand a single word of it; without these one wanders about in a dark labyrinth.”(p. 4)

Mayr noted that no sooner did the mechanistic view rise to prominence that a counterview arose to challenge it. Mayr wrote that “From Galileo to modern times there has been a seesawing in biology between strictly mechanistic and more vitalistic explanations of life.”(p. 5) Vitalism (the belief that living organisms have a special vital force or vital substance that cannot be found in inert manner) “From its emergence in the 17th century, was decidedly an antimovement. It was a rebellion against the mechanistic philosophy of the Scientific Revolution and against physicalism from Galileo to Newton. It passionately resisted the doctrine that the animal is nothing but a machine and that all manifestations of life can be exhaustively explained as matter in motion. But as decisive and convincing as the vitalists were in their rejection of the Cartesian model, they were equally decisive and unconvincing in their own explanatory endeavors.”(p. 9)

The vitalist and mechanistic world views both sought to explain “what is life,” and both were discredited in the eyes of most biologists by the middle of the 20th century. (Mayr provides a substantial bit of historical detail about vitalism and its subsequent decline) Mayr related how the physiologist J.S. Haldane (1931) argued that “Biologists have almost unanimously abandoned vitalism as an acknowledged belief. At the same time a purely mechanistic interpretation cannot account for the coordination that is so characteristic of life.”(p. 16)

According to Mayr the demise of vitalism didn’t trumpet the victory of mechanicism but rather gave birth to organicism. “According to W.E. Ritter who coined the term organicism in 1919 “Wholes are so related to their parts that not only does the existence of the whole depend on the orderly cooperation and interdependence of its parts, but the whole exercises a measure of the determinative control over its parts.” (p. 17) Organicism clashed with the mechanists’ faith in the use of reductionism. Organist believed “a whole is more than the sum of its parts.” Mayr pointed out that “For reductionsists, the problem of explanation is in principle resolved as soon as the reduction to the smallest component has been accomplished. They claim that as soon as one has completed the inventory of these components and has determined the function of each of them, it should be an easy task to explain also everything observed at the higher levels of organization.”(p. 17) However, “The organicists demonstrated that this claim is simply not true, because explanatory reductionism is quite unable to explain characteristics of organisms that emerge at higher levels of organization.” (p.18)

Mayr believes that “The pioneers of holism (for example, ES Russell and JS Haldane) argued effectively against the reductionist approach and described convincingly how well a holistic approach fits the phenomena of behavior and development. But they failed to explain the actual nature of the holistic phenomena.” But Mayr goes on to say that “Alex Novikoff (1947), however, spelled out in considerable detail why an explanation of living organisms has to be holistic. ‘What are wholes on one level becomes parts on a higher one…both parts and wholes are material entities, and integration results from the interaction of parts as a consequence of their properties.’ Holism, since it rejects reduction, ‘does not regard living organisms as machines made of a multitude of discrete parts (physico-chemical units), removable like pistons of an engine and capable of description without regard to the system from which they are removed.’ Owing to the interaction of the parts, a description of the isolated parts fails to convey the properties of the system as a whole. It is the organization of these parts that control the entire system.” (p. 18)

In summary Mayr showed that “organicism is best characterized by the dual belief in the importance of considering the organism as a whole, and at the same time the firm conviction that this wholeness is not to be considered something mysteriously closed to analysis but that it should be studied and analyzed by choosing the right level of analysis…Every system, every integron, loses some of its characteristics when taken apart, and many of the important interactions of components of an organism do not occur at the physiochemical level but at a higher level of integration.”(p.20)

The origins of biological science

For Mayr “The scientific disciplines that gave rise to the prevailing concept of science during the Scientific Revolution (that remarkable achievement of the human intellect characterized by the names Copernicus, Galileo, Kepler, Newton, Descartes, and Leibniz) were mathematics, mechanics and astronomy…The ideals of this new, rational science were objectivity, empiricism, inductivism, and an endeavor to eliminate all remnants of metaphysics.” However, Mayr observed that “Virtually all architects of the Scientific Revolution remained devout Christians, however; and, not surprisingly, the kind of science they created was very much a branch of the Christian faith. In this view, the world was created by God and thus it could not be chaotic. It was governed by His laws, which, because they were God’s laws, were universal…The task of God’s science, then, was to find these universal laws, to find the ultimate truth of everything as embodied in these laws, and to test their truth by way of predictions and experiments.” (pp. 26-27)

For Mayr the science of biology laid dormant until the late 19th century because scientists believed that “the answer to the most basic problems in the study of living organisms depended on whether or not one invoked the hand of God. This was particularly true for all questions of origin (the subject matter of interest to creationists) and design (the subject matter of interest to natural theologians). (p.29) Additionally, “The acceptance of mechanics as exemplar of science led to the belief that organisms are in no way different from inert matter. From this followed logically the conclusion that the goal of science was to reduce all of biology to the laws of chemistry and physics. In due time developments in biology made this position untenable.”(p.30)