Film can be studied for itself as a primary source and aesthetic artefact, or it can be used as a teaching aid in the study of ordinary bread-and-butter history. This distinction, corresponding to the traditional one between the historian's primary and his secondary sources, has almost become a cliche in the discussion of the use of film to the university historian. It is a distinction which we forget at our peril, yet which, if applied too rigidly, can lead to a misunderstanding of the complexity and richness of film as a medium of communication, and to a neglect of what can be called the ‘magic’ of film. In practical classroom situations, university teachers use both compilations which are clearly ‘secondary’, and feature film and original documentaries and newsreels, which are clearly ‘primary’; yet the latter are often, and quite properly, used as much as a basis for broader historical discussion as for narrower source criticism.

However, let us start by establishing firmly the difference between whole archive film of various types, and specially made ‘secondary’ film, whether made by historians or by the professionals of the film and television world (at present, and for the foreseeable future, a fair proportion of films actually used in our universities have been originated by the broadcasting networks).