This paper draws on Thomas Kuhn’s The Structure of Scientific Revolutions, but it is neither an exposition nor a critique of that book and uses certain concepts from it as a springboard for reflections on the nature of crisis. Kuhn’s key term was paradigm; however, the primary focus of this paper will be on the intertwined concepts of normal and revolutionary science, and one of the concepts central to the latter: crisis. I ask whether crisis necessarily constitutes a break in continuity or practice, together with our understanding of that practice, thereby generating an inability to ‘think through’ crisis (the radical rupture thesis), or whether crisis can be conceived in an evolutionary fashion as a dialectical progression in which tensions and oppositions do not necessarily signify (or result in) a breakdown of the system or our understanding of it (the dialectical thesis). One of the underlying questions to be considered is precisely how far the analogy between natural science and politics is valid. Here my purpose is primarily to explore the issue and to raise questions rather than to provide concrete answers.