In the eighteenth century there was lively interest in Natural Theology: The essential arguments were brilliantly stated by David Hume in his Dialogues Concerning Natural Religion. Thirty years later came Paley’s Evidences of the Existence and Attributes of the Deity Collected from the Appearances of Nature. Its success was very likely responsible for the endowed Lectures which ensued—the Gifford, Lectures, “for Promoting, Advancing, Teaching, and Diffusing the Study of Natural Theology”; the Bridgewater Treatises “on the Power, Wisdom and Goodness of God, as manifested in the Creation”; the Silliman Lectures “designed to illustrate the presence and providence of God as manifested in the natural and moral world”; and others.
Professor Dubos, as Silliman Lecturer, is in the same tacit predicament as so many of his post-Darwinian fellow lecturers in these series: He extricates himself, as some of them have, by duly presenting the “appearances of nature” as scientific study has revealed them, and eschewing any inference at all about God’s attributes. The argument from design, for what it is worth, is left to speak for itself.
Adaptation, Dr. Dubos’s theme, is not new in this context. The first Bridgewater Treatise was on the Adaptation of External Nature to the Moral and Intellectual Constitution of Man; and the second dealt with the Adaptation of External Nature to the Physical Condition of Man. Dr. Dubos deals with the converse issue, man’s adaptation to the conditions of external nature. It is a significant transposition: Man is no longer viewed as central and determinant; he must change to fit his surroundings or he cannot survive. The thirty-ninth Silliman Lecture is an erudite, vigorous statement of the necessity for adaptation, its dangers and demands, and especially its medical implications.
Adaptation is a biological concept which has been extended into the social sciences, where it takes on a more diffuse meaning, and has as its aim not only survival but also improved function (including the functioning of social systems). Psychological and social factors have to be taken into account as much as biological ones. Thus the ability of human beings to learn widens enormously the range of adaptive responses, and at the same time creates conditions in which man’s adaptive responses become crucially necessary. Dr. Dubos does not trouble himself or the reader with definitions and niceties of approach, but goes straight into his thesis and expounds it with enthusiasm derived from intensive firsthand experience of relevant fields and an exceptional acquaintance with many branches of learning. He speaks of his own area of research when he describes the role of gastro-intestinal flora, and the development of immunity to tuberculosis.
AT THE OUTSET Professor Dubos makes some of his primary assumptions clear. The exact sciences tell us much about man’s nature in its physico-chemical aspects, but they fail to account for what is particularly human, the way in which our responses are determined by the symbolic interpretation we attach to stimuli when they are experienced. The problem of adaptation …