I want to claim that healthy science involves, at all times, a synchronic tensed suspension of consensus and dissensus between working scientists, which provides both the variety of opinion and the agreement in opinion essential to coherent scientific progress. The early philosophers of science and the early sociologists of science seem both to have worked with an oversocialized conception of scientific thought, philosophers regarding lapses from postulated objective standards of rationality as the unfortunate intrusion of emotional and personal factors into scientific reasoning, and the sociologists viewing the breakdown of shared values within research groups as the inexplicable accompaniment of emerging anomalies. More recently, sociologists working with a conception of the social construction of scientific thought have reversed the emphasis, suggesting that consensus is essentially a temporary and unstable phase in scientific development, and philosophers have recently crafted a new form of philosophical scepticism for science in suggesting that it is impossible ever to establish that a genuine consensus exists between scientists.