24 SOCIAL SCIENTIST Kuhn's work bared the other side of scientific activity — "normal science" — a patient conformism to basic categories while developing a more complete view of the world in terms of these categories. To Pop-perians, this was anathema, as robbing science of its critical content was to disarm it in its battle against ideology. Kuhn showed that while in terms of observable facts, the effect of a paradigm shift was minor, the reordering of categories of science accompanying a paradigm shift was of major historical significance. Scientific "facts" can be perceived only in terms of categories of an existing theoretical structure. Extra-ordinary science or revolutionary science has precisely the character that it seeks to change the basic framework within which scientific facts are studied. The changed framework can not be derived out of the existing one through a mere extenstion — it is incompatible with the existing one. To Kuhn however, the explanations for paradigm shifts are to be sought in the sociological domain, not withstanding his protestations [6j. Thus, progress in science was replaced by consensus on scientific categories arrived at sociologically by a community of scientists. If one were to examine the relation of such theories of science to the evolution of science, one can perceive the replacement of continuity models of scientific development by the Popperian discontinuity model. In the Popperian framework however, the discontinuities were continuous in nature. Kuhn restored a certain balance to this model by positing discontinuities as well as continuities in the evolutionary process. In so doing, he was to relegate the evolutionary discontinuities in science to the realm of meta science rather than science proper. "Normal science" was problem solving with a given set of categories and theories while extra-ordinary science was the replacement such categories by mutual consent of the scientists. Implicit in Kuhn's work is the belief that under conditions of normal science, at a given point of time there is only one paradigm [7]. Earlier it was thought that contending paradigms without resolution was a phenomena in relatively underdeveloped sciences. Contending paradigms, it was felt, can not sustain a problem solving tradition. However, as can be seen now, alternate frameworks exist even in physics and they do sustain extremely active problem solving traditions. Kuhn's view of science has come under criticism from many quarters. It is not the intention of this paper to elaborate on the problems of a Kuh-nian framework with its implicit relativistic assumptions. We are interested here in examining how science can retain its validity in spite of falsification and paradigm shifts. We will also see how falsification and paradigm shifts stand in relation to multiple paradigms which are increasingly found even in the mature sciences. However, two issues regarding Kuhnian framework will be touched upon here, as they have a bearing on the question of ideology and its relation to science. Kuhn's attempt to locate in sociology of the scientific community the mode of paradigm change can be considered a valid enquiry