Herbert Spencer was the most influential Anglophone sociologist of the nineteenth century, but his contributions are now largely forgotten. It is argued, however, that the clarity of his understanding of the use of biological metaphors in sociology gives his work a power which is worth rediscovering. This proposition is pursued through a discussion of his treatment of the professions and their role in industrial societies. His approach is compared with the "ecological" perspective of sociologists in the Chicago tradition, notably Andrew (...) Abbott. It is suggested that Spencer's work rests on an alternative interpretation of the ecological model; this opens the way to an understanding of the regulative structures of "the system of the profession," which fills a major gap in Abbott's account. (shrink)