C.F. Goodey's A History of Intelligence and ‘Intellectual Disability’ is an ambitious attempt to demonstrate the ways in which certain activities came to be classified as intelligent and others not and the impact of these processes on developing concepts of what it means to be human. Building on over twenty years of research, the book's basic premise is that rather than being innate, the notion that intelligence defines membership of the human species is, in fact, a modern development. Concepts of ‘intelligence’ and ‘intellectual disability’ are not fixed in nature, but are historically contingent and developments in the early modern period are crucial to the making of modern psychology. Goodey develops this argument over the course of eighteen chapters. The result is a remarkably wide-ranging study that attempts no less than an intellectual history of the intellect. Drawing on sources from classical philosophy, through early modern conduct books, theological literature and medical texts, to modern works of psychology and genetics, the book tells a complex story in which the ‘intellectually disabled’ came to be denied citizenship and membership of the human species at the same time as their existence became vital to defining ‘intelligence’ and establishing its social importance.

Goodey begins his history, appropriately, by examining the classical authorities upon which Renaissance authors drew by examining the criteria for defining problematic intellects in ancient Greece. Exploring the writings of Plato and Aristotle shows the difficulty of transposing modern concepts of disability onto the past. Plato's concept of ‘learning difficulty’ cannot be equated with modern learning disability since slow or difficult learning was not deemed by the philosopher to disqualify a person from public life. Furthermore, although Aristotle is often credited with establishing rationality as the criterion for membership of the human species, a careful reading of his work demonstrates that rationality was not in fact seen as the sole defining feature of humanity. Over the following chapters, Goodey traces the historical development of what are often taken for granted as ‘natural’ signs of human intelligence, such as speed of thought and ability to think abstractly, showing how each of these developed in specific historical contexts. Quick-wittedness, for instance, became a valued gentlemanly quality under the influence of Renaissance humanism and of developments both in the expansion of the state (which increased the honour of public service) and in the growth of commerce.

The central part of the book draws upon anthropological models of in-group and out-group membership in order to explore the interplay between honour, grace and intelligence in early modern thought. Goodey demonstrates important overlap between the three, showing the ways in which modern psychology developed out of these distinctly early modern modes of thought and social organization. The early modern ‘honour society’ created an out-group of excluded. As intelligence or ‘wit’ became increasingly valued as a hallmark of gentility, the excluded incorporated a wide social group – ‘idiocy’ was a characteristic of the lower orders and racial ‘others’. The book also demonstrates the religious origins of modern concepts of intelligence in the division between the ‘elect’ and the ‘reprobate’. As focus began to shift towards recognizing the signs of election, particularly in Calvinist thought, so ‘understanding’ was elevated as evidence for human perfection.

The book also explores changing medical theories regarding the causation of intellectual disability. Comparing early modern medical frameworks with modern genetics, the book makes some fascinating observations on the parallels between Renaissance medicine and behavioural-phenotype theory, in spite of their different biological and social components. Goodey also demonstrates the overlap between physical and intellectual disability in the early modern period. Turning its attention to the ‘ethics of exceptionalism’, the book examines the status of the ‘changeling’ in early modern thought. In another revealing discussion, Goodey shows how changeling stories (often dismissed by modern psychologists as ‘folkloric’) bear a striking resemblance to the bereavement analogy that is used in modern coping theory, where parents need to grieve for the absence of a ‘normal’ child as part of the process of coming to terms with having a disabled one. Early modern stories of changelings – where ‘healthy’ children are substituted with disabled ones – follow a similar pattern. The history of changelings also raises questions about the balance between ‘natural’, ‘unnatural’ and ‘praeternatural’ causes of disability, and the role of parental responsibility. The book culminates with a study of John Locke's Essay Concerning Human Understanding, which is identified as the transition point from premodern to modern psychological explanations. In Enlightenment notions of ‘man’ the human mind is established as ‘a natural and quasi-secular realm of its own’ (p. 346). The ascent of the intellect, and the identification of ‘intellectual disability’ as its generalized opposite, were simultaneous developments, dependent upon each other.

This is a fascinating book that shows quite brilliantly the interconnection between socio-economic, religious and medical modes of thought in the history of the intellect. The book makes few references to recent research in disability history – Lennard J. Davis's work on the development of the concept of ‘normality’, for example, addresses similar themes, and there is no mention of Jonathan Andrews's pathbreaking work on the history of early modern idiocy – but it shares the objectives of this wider body of work in challenging the notion of disability as being ‘fixed’ in nature. As Goodey argues, people in the past had different ideas about disability because they asked different questions about their world. The challenges set out in Goodey's arguments seem directed first and foremost at modern practitioners of psychology, showing how current scientific ideas owe more to an early modern intellectual world governed by God and the Devil and stratified by seemingly archaic codes of honour than is often acknowledged. This rigorous, provocative and at times difficult book establishes new directions in the history of science and disability and is required reading for practitioners in both these areas.