the subject said, “I’m not even sure now what a spade looks like. My God!” The sense of crisis and anxiety grows with recognition of the many smaller anomalies that had been overlooked. The entire foundation of the field seems unstable, and doubts arise about the value of familiar paradigminspired experiments.
Anxiety creates a willingness, even a need, to consider alternative paradigms. The field splits into two camps: that which suggests competing piecemeal solutions to the various anomalies, clinging to the old paradigm, and that which considers alternative paradigms. This second group of investigators refuses to accept rationalizations of the major anomaly. These scientists explore the anomaly more deeply and attempt to characterize it, simultaneously looking for invalid assumptions.
“That is in the end the only kind of courage that is required of us: the courage to face the strangest, most unusual, most inexplicable experiences that can meet u s . ” [Rilke, 1875-1926]
Reconciliation of the problems seldom comes rapidly. The period of paradigm crisis can last for years or decades, and anxiety may become discouragement. Perhaps the new paradigm will require new technology and its attendant new insights. Almost always, the new paradigm is discovered by someone young or new to the field, someone less hampered than most by perspectives and assumptions of the old paradigm. The new paradigm may be a radical modification of the old paradigm. The old paradigm may be seen as a special limiting case of the new one, as was the case for Newtonian dynamics when seen from the perspective of Einstein’s dynamics.
Paradigm change may be led by a few people, but usually it involves many people working over a period of several years. Within the subgroup that had been bothered by the anomalies, a consensus of both experimenters and theoreticians emerges, concerning the advantages of a new paradigm over the old one. Simultaneous independent discoveries are likely. Now is the most exciting time, with the (mostly young) proponents of the new paradigm exploring the range of its applications. The pace of change is extremely fast: only those who are attending conferences, receiving preprints, and learning the new jargon are fully aware of these changes.
Polarization of old and new schools continues well beyond the acceptance by the majority of the new paradigm. The old and new paradigms identify different subjects as appropriate for research and emphasize controlling different variables. Communication between the two schools breaks down. Neither paradigm accounts for every observation; thus each group can point to anomalies or weaknesses in the other paradigm. But with time the demand of the new majority is fulfilled: “convert or be ignored” [Kuhn, 1970].
These interpretations of the pattern of change in science are those of Thomas Kuhn; they are not accepted universally. Stephen Toulmin [1967] suggested that scientific change is more evolutionary than Kuhn has pictured it. Toulmin used the analogy of biological evolution, emphasizing that competing theories abound, and the more successful ones eventually triumph. The analogy was unfortunate, for most paleontologists now see evolution as dominantly episodic or revolutionary -- a punctuated equilibrium [Eldredge and Gould, 1972].
Scientific change is punctuated illumination. For both scientific and biological evolution, relatively stable periods alternate with periods of dynamic change, but no one suggests that the stabler times are stagnant. Mannoia [1980] summarized the philosophical trend of the seventies as moving away from the Kuhn/Toulmin perspectives, toward an ‘historical realism’, but I think that the jury is still out.
