TRADITIONALLY the history of the Western world has been divided, like ancient Gaul, into three parts, but the more significant division is into what precedes the scientific revolution of the sixteenth century and everything that has occurred since. For the events of the latter period are unique. What makes them so is the advent of modern science. Modern science has reoriented men's thinking about the nature of the world in which they live and through its technological fruits has transformed their institutions. The whole of modern times has been one vast slow revolution, a revolution still proceeding. This intellectual and cultural revolution has passed through five main phases as one area of experience after another has been yielded, reluctantly, as a proper field of scientific inquiry. The phases of this revolution may be associated with certain representative names: (1) Space-- Copernicus, "On the Revolutions of the Heavenly Bodies" ( 1543); (2) Time-- Lyell, "The Principles of Geology" ( 1830- 32); (3) Life-- Darwin, "The Origin of Species" ( 1859); (4) Society-- Marx, "Capital" ( 1867); (5) Mind-- Freud, "The Interpretation of Dreams" ( 1900); (6) Method-- Einstein, "The Special Theory of Relativity" ( 1905).
Note the accelerating pace of this development. And observe that this gradual conquest begins with what is most remote from men's inclinations and desires, mathematics, astronomy, and physics. This first period of the expansion of science culminates in the synthesis made by Newton at the end of the seventeenth century. But it is not until the nineteenth century that a real beginning is made in the historical sciences-- those for which time is the focal concept--of geology, biology, and sociology by men such as Lyell, Darwin, and Marx. Finally, the innermost citadel of resistance to the application of scientific method, the human personality itself, is attacked by Freud; and the last pretence that we can know reality as it is in itself, the very quest for certainty, is abandoned in principle with the general acceptance of Einstein's theory of relativity. The outlines of science as a human construction may therefore now be said to be complete.
The result of this immense shift in the climate of opinion, together with the cumulative effect of technology, has been to engraft upon the historical process a new dimension. Modern science and technology have imposed a radically different kind of organization upon our lives, making our pattern of culture--one in which "atomic" and "automation" are ordinary words--entirely foreign to anything ever before seen in the world.
Of the successive phases in this advance the extension of scientific inquiry into the biological realm was the most difficult to accept. Newtonian science had been thoroughly assimilated to traditional beliefs by the construction of a system of natural theology in which it was affirmed that all physical events happen in accordance with rational laws and have, when properly understood, a use. Therefore, the progress of scientific knowledge revealed more and more details of a cosmic plan. The world described by the scientists was a second revelation expressed not in words but in events occurring in space and time. The favorite illustrations of this organization of the world by an intelligent power were drawn from the field of biology. How, for