Abstract

These introductory remarks are unorthodox in many respects. The deviance from usual practice is justified by the extreme importance I attach to the subject matter of this special issue. I want to convey to the reader a sense of why I think controversies, particularly in science, are so crucial, and to propose a different way of thinking about them. This mandates, in the limited space available, a compact presentation, omitting supporting arguments and necessary elaboration — for which the reader is referred to the bibliography.