Gaines Post (1902–87) was a historian of medieval thought, particularly adept at mapping the interface between scholasticism and law. His Harvard PhD thesis was presented in 1931 as one of the last supervised by Charles Homer Haskins (1870–1937). It is here brought before a wider public as a result of the enthusiasm of William Courtenay, like both Haskins and Post before him a distinguished professor at the University of Wisconsin-Madison. Post himself published only two of its ten chapters. The other eight have until now languished in typescript. As here revealed, not only is this work of the highest scholarly refinement, but an important witness to the transmission of ideas from the age of Haskins and Hastings Rashdell (1858–1924). Rashdell's Universities (1895) is cited by Post on virtually every page. Equally ubiquitous, albeit as target as much as model, Heinrich Denifle's Die Universitäten des Mittelalters (1885) serves as the antithesis against which Post's argument is constructed. Put simply, Post argues that the papacy, although central to the growth of the universities, acted more as accidental midwife than as in any sense institutional ‘founder’. In response to the emergence of the schools, above all of Paris, popes, from Alexander iii onwards, sought to control the licensing and provision of teaching, to protect doctrinal truth, to encourage theology in competition with more marketable skills such as law or medicine, and to prevent the sale for undue profit of learning that should be made freely available to all. By transforming the cathedral's chancellorship into what was essentially a papally sponsored office, successive popes helped to smooth the path by which the University of Paris, and subsequently Oxford, broke free from local or episcopal control. The emergence of the licentia ubique docendi, to begin with a more or less casual development, in turn provoked a canonical distinction between merely local schools, studia particularia and true universities such as Paris, Bologna or Oxford. Only in such studia generalia did the full range of dispensations apply, allowing students and teachers to absent themselves from benefices elsewhere. All of this might be considered caviar to the general, were it not for the forensic way in which Post deploys his evidence, in particular from the canonists. Here he made precocious and in many ways unsurpassed use of decretal commentaries, for the most part from manuscripts in Rome. Behind all of this lay the paradox of an essentially centralising and anti-communal institution, the papacy, supporting the creation of powerful new corporations that in due course were to challenge the very authority that had first encouraged their emergence. When Post wrote, much of the early institutional history of the schools, even of Paris, remained obscure. Subsequent researches have brought to light a wealth of detail, not least the earliest statutes of the University of Cambridge (as revealed by M. B. Hackett in 1970, from a manuscript in the Biblioteca Angelica, tantalisingly close to Haskins and Post's Roman stamping grounds). For Oxford, as for most other studia generalia, there is now a magnificent multi-volume history. For Paris, thanks to the researches of John Baldwin and others, the current state of play is best set out in Ian Wei's Intellectual culture in medieval Paris (Cambridge 2012). The broader trajectory that Post traces here, none the less, remains unchallenged, with the papacy not as proud parent but as the universities' sometimes absentee, sometimes sinisterly attentive godfather. Dry and precise as Post's findings appear, they stand in welcome contrast to the laudatio parentum and naming of parts with which most modern PhD theses are encumbered and offer a wealth of detail, particularly in the footnotes, that can still be mined with profit. As editor, Courtenay supplies an index, and tidies up various inconsistencies. There are misprints, some minor (stadium for studium, p. 157), some more alarming (Clement iii for Nicholas iii, p. 235). More generally, one regrets that Courtenay, a towering figure in his field, contributes so brief and reticent an introduction. A modern reader might have appreciated advice on the chief advances made since 1931, not least by Pierre Michaud-Quantin's Universitas (Paris 1970), a book still shamefully underrated outside France, placing the oath at the centre of all things communal and hence corporate, in ways that Post might have been fascinated to discover. Notice might have been supplied of the autobiography of Gaines Post Jr (Memoirs of a Cold War son, Iowa City 2000), not least because it answers, in personal detail, a question posed in Courtenay's introduction: why did Post fail to transform his thesis into a book? We might also speculate, more broadly, on the unrivalled contribution made by American scholars to the history of the medieval universities. From Henry Adams and Henry Charles Lea onwards, this was a topic of contemporary rather than purely antiquarian concern. Both on American campuses and in the governmental circles to which such campuses enjoyed privileged access, there was and remains an unresolved dilemma. Were universities to be officially monitored or controlled, or should they be permitted as self-governing, and essentially self-financing entities, both to think and to develop freely? In the age of Taft and Woodrow Wilson, relations between medieval university and papacy, universal and specific corporate authority, agency and investigation, were of immediate relevance. In the compromises achieved here lay much of the impetus for Post's research. Those compromises remain central to a controversy (in the UK more urgent than ever) over the extent to which state or market sponsorship of the universities should involve either financing or control. As Gaines Post or Haskins himself might have put it, amongst university administrators and those entrusted with the guardianship of knowledge ‘Quis custodiet ipsos custodes?’