Simon Jarrett has written a history about the ideas of idiocy and adjacent concepts, in which he demonstrates that the idiot can be seen as a crucial figure in the history of medicalization and racialization alike. He offers a highly readable account of ideas about those they called idiots, full of surprising encounters between minds that may be familiar, if not for their ideas about idiots, and delivering a carefully optimistic message in the end. It is the idea of the disabled mind that is the subject of the book, and this idea is traced as something embedded in a variety of cultural practices. It is no small feat to pull this together into a compelling narrative.

The story is narrated in broad strokes, covering three centuries and including ideas articulated in France and the United States as well as in the United Kingdom. It is organized in three parts, telling a story in three acts: in the eighteenth century, those they called idiots were integrated in society. They were not necessarily respected, but they were accepted as a part of the communities they lived in. In the nineteenth century, they became racialized and medicalized and incarcerated in large institutions. The invention of institutional ‘care’ is a dark moment in this history – and the author does not hide his value judgement, referring to ‘the murderous beast of the institution’ (p. 305). The second act culminates in the eugenic movement, with its vision of eradicating those they called idiots altogether. But in the midst of this movement, already, new ideas about community care were articulated. The third act deals with ideas of deinstitutionalization and community care. After more than a century of harsh incarceration we are maybe completing the circle, as new ideas of deinstitutionalization have carried the promise of a reintegration of the disabled in the community, and thereby a more generous conception of community.

The author uses a wide range of primary sources. In dealing with the first period, Jarrett brings into light rarely seen sources, such as court cases, joke collections and slang dictionaries, and teases out various meanings of ‘idiot’ from them. This material is particularly original and substantively expands the social substratum for this history of ideas. As to the second period, it is dominated by sources more familiar from intellectual history; and for the third period, sources produced from the vast modern bureaucracy become important. An impressive aspect of the author's use of these sources is the way that the history of intellectual disablement is widened out to become a broad cultural history, which includes intellectual history, history of medicine and science and the history of social policy.

At the heart of this history is a historical phenomenon that is also considered a moral problem, which is that of institutionalization (‘the great incarceration’). The large institutions for people with disabled minds are, for Jarrett, ‘murderous beasts’ (p. 305). The construction of them (and their equivalents for the insane) in the nineteenth century involved the exclusion of those they called idiots from their communities, where they had been regarded as a part of the social fabric in previous centuries. How was this great exclusion possible? The author claims it was possible largely through the interference of men of science, which in most cases means medical professionals. The history of the idea of the disabled mind ominously overlaps with the history of the professionalization of medicine as the book describes how medical men inserted themselves in courts of law and related bureaucracies, claiming a privileged knowledge of the mind. Though they often did so by asserting that the medical perspective represented a more humane road than the alternatives, the real consequence was to single out people who did not belong to the increasingly narrow category of normal human beings.

Thus a dominant explanation of the history the author so skilfully weaves together is to be found in medicalization, which can here be regarded as a narrative as much as a theory. Medicalization stresses the negative consequences of medical interpretations of the world. In Jarrett's history, medicine, and science more broadly, are mainly a dark force. To take but one example, the invention of the intelligence quotient in the early twentieth century is a seminal event in this story, as in Jarrett's view it ‘sealed the scientific colonization of mental deficiency’ (p. 261). The invention was, writes Jarrett, ‘peddled’ with ‘enthusiasm’ by psychologists and this enthusiasm reflected the psychologists’ ‘desperation’ to be seen as practitioners of an exact science (pp. 261–2). Here the author perpetuates Steven Jay Gould's critical perspective on intelligence testing from The Mismeasure of Man (1981). As a narrative this is clear and persuasive. As an explanation of the formation and development of scientific ideas it may, on the contrary, be seen as reductive. Other recent scholarship on the history of intelligence testing tends to indicate more complexity and less enthusiasm involved in the invention and spread of this technology.

That said, this is a well-informed, deeply researched and lucidly written history of the idea of the disabled mind that impresses on many levels. It can be read by the specialist and the curious beginner alike and is strongly recommended for anyone interested in the history of psychiatry, disability studies or the history of racialization.