Long before the cell, the fibre played – as a conceptual tool, an object of empirical investigation and a cultural phenomenon – a central, unifying role in early modern debates about the order of organised bodies that took place in various emerging disciplines, such as comparative anatomy, physiology, medical pathology and therapeutics, psychology, and anthropology. Accessible to a broad readership, Ishizuka’s latest book makes an important contribution to the study of this concept in the early modern world. With a focus on the British Enlightenment, Ishizuka examines and systemically relates all three aspects of fibres within a single long-term study that stretches from the second half of the seventeenth to the first decades of the nineteenth century.

The book is divided into three parts that are again subdivided into sequentially numbered chapters. At the end of each chapter, the reader finds a short summary and a list of the cited literature. The book ends with a general conclusion, a complete bibliography and a combined index of subjects and persons. The first part retraces the ‘emergence of the fiber-body’ between 1650 and 1700, the second part centres on the different models of fibre-bodies in eighteenth-century medicine, and the third part focuses on the relation between these bodies and the ‘culture’ to which they belong.

In the first part, Ishizuka’s main protagonist is Nehemiah Grew (1641–1712), a plant anatomist who argued that fibres were the smallest building blocks of the bodies of plants and animals. With the help of microscopes, Grew visualised in various illustrations, like his Italian colleague Marcello Malpighi, the entire body of plants as a vessel of interwoven fibres of different kinds. Ishizuka discusses some of these illustrations.

At the end of the first part, he points to a conceptual shift that began in the second half of the seventeenth century, but only unfolded its discursive dynamics in the following century. It was a shift from representations of fibres as passive structural building blocks that form vessels and various membranes to models of fibres as minima naturalia that could move themselves, react to outer stimuli and interact with each other within the networks of entire fibre-bodies. In Ishizuka’s own words, this was a ‘radical step within medical theory to recognise the significance of the fibers as not only the component of the vessel but also the essential agent to the solids as a whole’ (p. 18).

In the beginning of the first chapter of the second part, Ishizuka locates this shift in the work of the Italian iatrochemist Giorgio Baglivi (1668–1707), and the distinction he made between muscular and membranous fibres. Without discussing Baglivi’s fibre-model in detail, Ishizuka mentions briefly the concept of of self-active fibres, formulated in 1651 by Francis Glisson (1596–1677), and moves on to the medical physiology of Herman Boerhaave (1668–1738) in order to highlight the transition from ‘ancient humoralism’ to ‘modern solidism’ (p. 243), for which fibres, and not liquids, were the main agents of organised bodies. Ishizuka also refers to the different usages of metaphors of weaving and of vibrating strings. The next three chapters focus on the ‘elasticity of animals fibers’ (ch. 3), on the ‘continuity and change’ of theories between mechanistic and vitalistic viewpoints (ch. 4), and the nascent field of ‘fiber psychology’ (ch. 5).

In the third and final part about the cultural embedment of fibre-bodies, the first chapter is about ‘The Fiber Body and the Baroque’ (ch. 6). Again, it begins in the second half of the seventeenth century. Drawing on Deleuze’s and Guattari’s analysis of the role of the fold in the Baroque, Ishizuka examines, in a period that stretches from Jan Swammerdam (1637–1680) and Nicolas Malebranche (1638–1715) to Georges Cheyne (1641–1743), the preformationist logic of folding and unfolding processes of membranes, themselves composed of interwoven fibres, during the development of organic beings. He concludes that, if ‘a garment with folds is another word for membrane, it is arguably true that the fiber body… is a product of the Baroque’ (p. 204). In the last chapter of this part (ch. 7), Ishizuka characterises the Age of Enlightenment as an age of sensibility and of new anthropologies that rely on centres of action and reaction both within living bodies and between these bodies and their environments. He dismisses the ‘hegemonic tone of historiography’ on the Enlightenment as an age of sensibility primarily dependent on models of brain–nerve connections, and convincingly argues that these models only emerged within an already existing debate about fibres and their different kinds of sensibilities and sympathies (p. 228).

With a general focus on the British Enlightenment and on the transition from ‘ancient humoralism’ to ‘modern solidism’, the great strength of Ishizuka’s book lies in his systemic, well-structured and meticulously documented long-term reconstruction of the development and the differentiation of a complex discourse about fibre-bodies, in which plants, animals and humans are just variations of a single model of organic organisation. It would certainly be interesting to explore various alternative perspectives about the cultural embedment of this discourse within the European context, especially the relation between ‘modern solidism’, Lockean empiricism and the materialist anthropologies of the so-called French ideologues, and to have a closer look at the microstructure of certain crucial shifts: for example, of Glisson’s concept of living matter and self-active fibers. But more important is the fact that all these aspects and questions have now to be re-discussed in the light of Ishizuka’s work.