Post-normal medicine.

Since the time of the Renaissance, the predominant metaphor for science has been the machine. Normal science is based on logical positivism—the belief that there is a single universal condition that can be validated and which accumulates with time building on what has gone before.1 With the application of science to medicine —‘the paradigm of certainty’—the modern world had arrived. With it came a view that the methods of science would transcend the psychological, social and cultural forces that previously had shaped world views. But is the clockwork universe finally running down? More recently, post-modernism has challenged the directives of science, emphasizing the process of knowing and the importance of how our minds form an integral part of that process. To the post-modern eye, the truth is not out there waiting to be revealed but something constructed by people, always provisional and contingent on context and power. A description of reality is an everchanging approximation which, as we make it more real, slips from our grasp.2 In a recent essay in the Lancet, Muir-Gray argued the case for post-modern medicine,3 an approach characterized by a plurality of meanings and contingencies. However, entrapped by the dictates of the modern and the realities of the post-modern, he misses an essential point—things have already moved on. Converging from a number of disciplines, post-normal science4 is beginning to recognize a world where many phenomena cannot be understood by breaking them down into their constituent elements and the application of analytical rule-based frameworks. Challenging both modernism and the restricted vision of post-modernism,5–7 its approach is holistic, reflecting diversity, rich interaction and complex dynamics: a meta-view of which the nihilism of post-modernity is seen merely as a limited gaze. Post-normal medicine does not replace traditional medicine or contest its claims to reliable knowledge, but offers a complementary perspective on the delivery and evolution of health care which we feel resonates with the experience of medical practitioners and the contingencies of the real world.