In 1938, as Director of the Natural Sciences Division of the Rockefeller Foundation, Warren Weaver coined the term molecular biology to describe the use of techniques from the physical sciences to study living matter. As he explained, this new hybrid science disputed the long-held view that “man as a conceiving, child-bearing, thinking, behaving, growing and finally dying organism presented problems that were in great part outside the range of rational analysis.”

Weaver had advocated heavily for the development of an experimental biology initiative. After joining the Rockefeller Foundation in 1932, he quickly moved to define the mission of the newly established Division of Natural Sciences. Though a mathematician by training, he was well aware of recent technological advances in physics and chemistry, and undertook a program of self-directed study to help him converse with scientific researchers. As he surveyed the field, Weaver came to believe that the Foundation could distinguish itself by promoting similar advances in the biological sciences.

As he later explained, the physical sciences had successfully addressed both “problems of simplicity” involving limited variables, and problems of “disorganized complexity” involving billions of variables calculable in theoretical terms. But the life sciences represented a middle ground of “organized complexity” in which a medium-sized number of variables could not be separated from each other because the research question was biological. A watch spring, he illustrated, could be removed from its casing and studied for its own properties, but a human heart could not be similarly removed from a living organism.

Molecular biology fit neatly within the Rockefeller Foundation’s strategic style in a number of ways. First, it was top-down science, since it relied on acquired expertise — a trained eye examining almost invisible particles, and a reliance upon precise and elaborate technologies. Second, it examined component parts in order to understand and eventually affect the larger whole, much as identifying “root causes” could change social problems. Third, in contrast to endowing entire institutions, funding this type of scientific research could be achieved through smaller, targeted grants, and this offered a measure of relief in the Depression-era climate of belt-tightening. Finally, program design required a managerial perspective that relied on educated hunches, strategic investments, and shrewd oversight — all qualities which Weaver possessed and cultivated in himself and his staff.

In that same year, the Rockefeller Foundation awarded research grants to Linus Pauling for research on the structure of hemoglobin. Under Weaver’s direction the Rockefeller Foundation became a primary funder of early research in molecular biology.