International Society for Science & Religion - Library Project

The Structure of Scientific Revolutions

by Thomas S. Kuhn

Introductory Essay by Michael Ruse

Since its publication in 1962, this book has had major influence, far beyond the thinkers in the history and philosophy of science at whom it was directed. The key notion of “paradigm” – a conceptual framework accepted by a community and offering avenues of research – has entered general discourse, and can now be found in arguments and discussions in many fields. Scholars working in religion and theology have found it a most useful tool of inquiry.

Kuhn argues that once a science matures and a paradigm is installed (e.g. Newtonian mechanics in physics or Lyellian uniformitarianism in geology), it cannot be easily challenged because it defines the very standards of what constitutes genuine science. This is normal science. Any difficulties that arise, anomalous results for instance, are regarded as puzzles rather than as problems. It is assumed that there must be a solution reconciling the paradigm with all new results and so failure to achieve such reconciliation reflects badly on the scientist rather than the paradigm.

However, sometimes irrefutable challenges repeatedly crop up and we find ourselves in a time of crisis. Such a crisis can give rise to a period of revolutionary science. But scientists cannot simply give up on the accepted paradigm, because that is to cease to do science as normally defined. Fortunately, it usually happens that someone – typically a fairly young researcher who knows the field but is not emotionally committed to the present paradigm – comes up with a new paradigm that offers fruitful areas of inquiry and, at least to some extent, reconciles with the new results that challenged the previous paradigm. The old paradigm is discarded, the new one taken up, and normal science resumes – the now-famous ‘paradigm shift’ has taken place.

Kuhn’s thesis is controversial in its claim that there are no outside standards by which to judge paradigms. Since they themselves make ‘reality’, defending them from within is circular and attacking them from without is meaningless (that is to say that critiques of the dominant paradigm can be attacked as failing to follow legitimate epistemological norms or to mesh with established fact). Some would go so far as to argue that this makes it all much more a matter of commitment and practice. Hence paradigm change cannot be justified in any objective way. Nor can old ideas simply be carried across revolutions. All must be rethought. A scientific revolution is therefore very much like a political (or religious) one. The winners rewrite the history books and make their way the only viable way. When challenged, Kuhn denied that this made him an out-and-out idealist but, compared to the realism of (the only contemporary work with the same importance and influence) Karl Popper’s Logic of Scientific Discovery, it is undeniable that the subjective plays a far greater role.

Much criticism has centered on the notion of paradigm, with justifiable complaints that it can mean many different things. Kuhn subsequently clarified his thinking and stressed that in important respects paradigms are metaphors – ways of looking at reality that create and provoke as much as they reflect. Critics also pointed out that rarely do scientific revolutions exactly conform to Kuhn’s pattern. Indeed, some argue that the biggest fault is to privilege revolutionary change in science when, in reality, it generally tends to be much more a matter of one small advance building on another. This is still a matter of ongoing debate.