Thomas Willard's PhD dissertation on ‘The life and works of Thomas Vaughan’, despite being completed at the University of Toronto in 1978, is still cited as one of the key works on the life and writing of the Welsh hermetic philosopher and alchemist. Now updated and published, Willard seeks to explore the importance of Vaughan as the writer of ‘the first English-language book with a dedication to the brothers of the Rosy Cross’. Willard presents Vaughan as the architect of a ‘Rosicrucian revival’, made possible due to the collapse of print censorship during the English Civil Wars, which sought to continue the work of the secretive (and possibly fictional) Rosicrucian fraternity formed in Germany in the early seventeenth century (pp. 1–3). The Rosicrucian manifestos promoted a ‘general reformation’ based on esoteric ancient knowledge, blending different traditions of mysticism, alchemy, hermeticism and occultism together, often resurging in popularity during times of social and political upheaval. Producing writings which were infamously described by Jonathan Swift as ‘unintelligible fustian’, Vaughan is a notoriously difficult figure to engage with. As Willard points out in his introduction, Vaughan ‘expresses no desire to reach a large audience’, often writing for a small circle of friends and interested contemporaries, and often ‘quotes widely and seldom translates what he quotes’. Despite the difficulty and obscurity of the sources, Willard aims to situate Vaughan within his specific historical context, reconstructing Vaughan's biographical details and offering ‘a reading of his texts, with attention to his sources, style, and influence’ (p. 1).

Chapter i presents Vaughan as a man shaped by conflict. At Oxford as a student at Jesus College in the late 1630s, he experienced the clash between Arminianism and Calvinism. During the Civil Wars, he found himself cast out of Oxford, instead being ordained by the bishop of St David's and returning to his home parish as vicar of Llansantffraed. In 1650 he would lose this benefice under the Act for the Better Propagation and Preaching of the Gospel in Wales, where Puritans targeted him for, amongst other things, his royalist tendencies. Willard suggests that Vaughan's interest in secret wisdom and the Rosicrucian reforms was, at least in part, a response to these clashes, and that through the study of magic, he could ‘chart a via media between superstition and iconoclasm’ (p. 13). What follows is an in-depth reconstruction of Vaughan's life and writings, tracing his first publications relating to Rosicrucianism, his career in medicine, his disagreements with the ‘Cambridge Platonist’ Henry More, his networks of patronage and his eventual death in 1666. There is much to digest here, including the fascinating links Vaughan had to the radical publisher Giles Calvert, whose bookshop was infamous for publishing works by Ranters, Levellers, Quakers and Behmenists, the latter group sharing a joint interest in the writings of Paracelsus (p. 35).

Chapter ii casts the net wider to explore Vaughan's reading and influences, exploring the range of sources he used which included platonic philosophy and writings on magic, the Kabbalah, alchemy and, of course, Rosicrucianism. Here we see Vaughan's unusual approach to existing Rosicrucian material. He did not speak German and had ‘little access to the evidence’ (p. 135) concerning the historical legitimacy of such a group. He also only cited the chief apologists for the Rosicrucians, Michael Maier and Robert Fludd, in passing, although Willard argues that they had more of an influence than Vaughan's sparse references suggest. Yet ‘by modern standards, Vaughan seems a highly uncritical reader’ and ‘other assumptions make it difficult to consider him an authority on anything’ (p. 143), an observation which Willard argues ties Vaughan to a synchronic construction of the past inherited from Renaissance writers. The exploration here again highlights just how complex an individual Vaughan truly was, and how challenging his writings can sometimes seem to modern readers.

Chapter iii provides a valuable contextualised exploration of Vaughan's language and outputs, offering a helpful overview for those seeking to familiarise themselves with his body of work and approach to writing. As Willard admits in the title of the chapter, these are works ‘not easily apprehended’ and ‘full of mystery’ (p. 147). It is commendable that the author seeks to impose some sense of order and structure onto what is a difficult group of texts. Chapter iv explores Vaughan's reputation amongst different critics and readers, which Willard argues forms ‘an instructive chapter in the history of taste’. Indeed, the author shows that Vaughan's writings can give important insight into the Restoration revolt against enthusiasm, the radical Enlightenment, the magical revival in Victorian England and ‘the occult establishment of more recent years’. As a result, Vaughan's position as a secretive and obscure writer is challenged, although Willard admits that the exploration ‘tells us more about Vaughan's readers than about Vaughan himself’ (p. 216).

The book's being based on Willard's PhD does, however, come with some drawbacks which, while not taking away from the important contribution of the book, do detract slightly. Most of the book is confined to four large chapters, some of which feel overly long, including the first which spans almost seventy pages and condenses what were the first several chapters of the original thesis. Some readers may also be alarmed at the statement in the acknowledgements that while the author had ‘updated scholarly references throughout, this remains in many ways a book of the days in the last century when I formed my basic understanding of Thomas Vaughan … the older references often precede the newer ones as acknowledgement of the scholars who helped shape my first views’ (p. xiii). While such an update to the scholarly references has undoubtedly been undertaken, the author is perhaps selling his work short by suggesting that his fundamental position on Vaughan has not changed in almost four decades in light of this new scholarship.

Nevertheless, this monograph will undoubtedly stand as the definitive reference work on the life and writings of Thomas Vaughan and will be of interest to scholars and students of early modern religion, philosophy, science and culture. Overall, the volume is well produced and contains few errors. It includes ten figures, many of which are in colour. Four short appendices on various annotations and excerpts relating to Vaughan will also be of use to future scholars. The volume features a substantial bibliography and thorough indexes of names, subjects and biblical citations.