Presentation by James Kneale. This presentation looks at the origin of the idea of 'moderate drinking', which animated debates about alcohol in Britain and elsewhere from the 1850s. This was partly the result of medical arguments about whether alcohol was a food, a medicine, or a poison, but, as the paper argues, it also reflected the concerns of life assurance firms. A number of different strategies by life assurers for separating moderate and excessive drinkers emerged, such as the use of a fixed daily limit considered to be safe. Such developments anticipate many of the questions surrounding uses of the 'unit' in Britain today, including: Is moderate drinking safe, or simply safer than excess? How does the public react when doctors disagree? And what happens when limits are set by complex networks of actors with different goals, rather than by simple, singular institutions like 'medicine' or 'the state'?