The Nature of Scientific Progress
Historians once presumed that ancient scientists focused on the same problems and used basically the same research methods as modern scientists. This led to a search for ancient precursors of currently accepted observations and theories, the determination of which would reveal a chronology of positive achievements by generations of scientists, in which each advance built upon previous discoveries.
In the aftermath of World War I and the vast, often destructive, changes to European civilization that resulted, the ideal of cumulative, positive scientific knowledge became a totem held by postwar society. Belgian-American scholar George Sarton (1884–1956), an essential force in establishing the history of science as an academic discipline, during the 1940s, viewed science as the only truly cumulative human activity, particularly in light of the capacity for events such as war to damage or destroy past evidence of civilized achievement.
In presenting this idea he wrote, "Science is systematized positive knowledge, or what has been taken as such at different ages and in different places." He therefore concluded that since "the acquisition and systematization of positive knowledge are the only human activities which are truly cumulative and progressive," then "the history of science is the only history which can illustrate the progress of mankind." Sarton's theories produced an internalist approach among the first generation of academically trained science historians, which appeared following World War II. Scholars typically eschewed consideration of society's role in the evolution of scientific thought, believing instead that science progresses largely without subjective, external influences.
The reassuring vision of cumulative and progressive science was shattered, however, in 1962 by American science historian Thomas Kuhn's book The Structure of Scientific Revolutions. Kuhn had participated in a pioneering attempt at Harvard University to teach science in the same manner that art, literature, and music are taught, that is, as a creative activity of the Western world. Technical facts and theories were presented not as useful bits of information but as examples of how science develops in a historical and philosophical framework. Approaching science history from this perspective, Kuhn did not see a continuous advancement of scientific achievement. For example, ancient and medieval work in physics, he believed, was not bad Newtonian physics laying the groundwork for modern ideas but was, rather, an earlier tradition that had been shattered by and replaced with a new and different one.
Kuhn envisioned periods of so-called normal science, during which work within a discipline proceeds according to certain research traditions, leading to the accumulation of facts and theories that correspond to accepted lines of thought. He asserted that the influence of particular values may at first be external to the scientific community, with social needs and values ultimately pushing certain questions to the forefront of scientific research. As a field of science develops, however, internal traditions replace external societal concerns, as research in the discipline comes to be based on a paradigm. Kuhn defined a paradigm as a set of generally accepted solutions to central problems within a science, and he believed that the paradigm provides a model for the consideration and solution of other problems relating to that field. However, use of the paradigm, according to Kuhn, is based on the training and subjective values of scientists, rather than on critical experimentation. Eventually the idea of a scientific paradigm took on a wider meaning than he had intended, so that the term now refers to the entire constellation of beliefs, values, and techniques that bind together a scientific community.
In time normal science may produce an anomaly, a new and unexpected phenomenon. Most anomalies are resolved in the terms of the paradigm, but those that are not can lead to a crisis, accompanied by large-scale paradigm destruction, a breakdown of normal science, and a proliferation of new and competing theories. Crisis leads to scientific revolution, a noncumulative, developmental episode in which an older paradigm is replaced with an incompatible new paradigm. As in political revolutions, Kuhn believed, the choice of a paradigm cannot be unequivocally settled by logic and experiment alone but is again subject to social pressures. He also denied that there exists one full, objective, true account of nature and so reasoned that scientific achievement cannot be measured in terms of how close it brings one to truth.
Even before Kuhn questioned the common notion of scientific progress as a clean, rational advance along a straight, ascending line, the Hungarian-British novelist Arthur Koestler (1905–1983), in The Sleepwalkers, described the history of cosmic theories, somewhat whimsically, as one of collective obsessions and controlled schizophrenias, with scientists caught up in feverish, intellectual dreams. Koestler's interest was in the psychological progress of discovery and in the converse process that blinds individuals toward truth, which, once perceived, is seemingly obvious. He highlighted unconscious biases and philosophical and political prejudices: the underlying beliefs, values, and worldviews that lie behind the choices scientists make. No branch of science, he asserted, ancient or modern, can claim freedom from metaphysical bias of one kind or another.
The American scientist and historian Gerald Holton developed an understanding of science similar to Kuhn's. For Holton science was not so much characterized by a collection of facts but, instead, by the actual problem-solving activities through which information is derived. Consequently, according to Holton, science historians should attempt to determine the observations and theories that confronted a scientist in a particular era, as well as the state of shared scientific knowledge in that time period, the creative insight that guided the scientist, and the possible connections between the scientist's work and his or her lifestyle, sociological setting, and cultural milieu.
Thus where Kuhn found paradigms, Holton found themata, in this case elements either constraining or motivating an individual scientist and sometimes guiding or polarizing the scientific community. He believed that a science historian's thematic analysis parallels the work of a folklorist or an anthropologist by seeking and identifying general, recurring themes that preoccupy individuals as well as society as a whole.
Holton also believed that while it would be possible to attempt a logical analysis or reconstruction of the means by which a discovery or theory had been verified or justified, it would be more difficult to analyze the steps leading to the initial conclusions. In the latter case, he asserted, the resulting analysis could differ drastically from reality, especially with regard to the steps that occurred during the relatively unpredictable creative phase of the original work.
Even in light of Kuhn's paradigms and Holton's themata, however, research into the history of science often remained marked by an idea, albeit implicit, that scientific knowledge ultimately is controlled by observation statements established beyond reasonable doubt through rigorous scientific method. In the 1970s and 1980s, however, this assumption was again challenged, this time by British sociologists. Working from a viewpoint similar to those of Kuhn and Holton, they analyzed the development of scientific knowledge in the manner used to examine the evolution of seemingly less objective, nonscientific fields, looking not to the impact of reason, argument, and evidence but to the influence of personal gain as well as social interests and forces. They asserted that scientific facts are socially constructed rather than discovered and that the cognitive content of science is determined primarily by social processes. By the same token, this theory may be self-contradictory, since it would suggest that, rather than providing an objective viewpoint, it has itself been shaped by the same social forces that have an impact on other information. In the 1990s sociologists began to retreat from the most extreme aspects of the theory, suggesting that scientific thought does, after all, possess special characteristics, including a certain amount of objectivity and epistemological authority that sometimes, if not always, raises it above other human endeavors.
Nonetheless, historical internalists have been largely supplanted by externalists. While the former tend to have considerable university training in science, enabling them to follow the logical and technical development of scientific ideas, the externalists commonly have a background in history and display a corresponding predilection for examining the relationship between science and social factors. This altered approach has led to charges by the science community that historians have lost their focus on the conceptual evolution of scientific ideas. They have been accused of leaning too heavily on the examination of social history and of having too little professional contact with university science programs.
At the same time academic history programs, having long ago expanded their subject matter beyond political and military history to include broader cultural topics, such as arts and letters, religion, economics, social status, and gender, have come to acknowledge the importance of science in history. Indeed, the British historian Herbert Butterfield, in his influential 1949 book, The Origins of Modern Science, argued that the scientific revolution of the 16th and 17th centuries "outshines everything since the rise of Christianity and reduces the Renaissance and Reformation to the rank of mere episodes."