The posthumous publication of Johannes Klatt's Onomasticon is a remarkable project. Klatt finished his work in 1892 but the original manuscript of this colossal book remained untouched until the editors of the present edition, Peter Flügel and Kornelius Krümpelmann, took on the herculean task to prepare Klatt's work for publication. The Jaina-Onomasticon is an alphabetically structured collection of biographical, literary-historical and geographical information related to the Jaina tradition, mostly in the post-canonical period. Klatt, who worked as a librarian at the Royal Library in Berlin, started collecting the data for this project from 1882 onwards and the outcome of his painstaking efforts is a highly useful document for the study of the history of Jainism.

The comprehensive introduction by Flügel provides a fascinating insight into the life of the nineteenth-century Indologist and librarian Johannes Emil Otto Klatt (1852–1903), and can be read as an independent study. Klatt studied under Albrecht Weber, and, together with Georg Bühler, established Jaina studies as an academic field. Yet, in contrast to Weber and Bühler, Klatt was never recognized as a major figure in the history of German Indology. Flügel's introduction offers a re-appreciation of Klatt's work and is interesting for at least two reasons. First, it provides the first comprehensive survey of Klatt's academic achievements. Second, it throws light on the way in which Indology was done in the nineteenth century and on the interactions between European academics and Indian informants during the colonial period. While the assessment of Klatt's academic output is primarily of interest to scholars in the field of Jaina studies, the analysis of the historical setting in which Klatt worked is valuable for anyone with an interest in the history of South Asian studies as a discipline. Even though the available sources to reconstruct Klatt's life are limited, Flügel manages to provide an engaging account of the personal and professional challenges that Klatt encountered during his career. The debates with his manager about the heavy workload and a lack of proper workspace at the library, which forced him to do his research primarily in the evenings, might sound very familiar to contemporary academics, just as does his struggle to secure a permanent position.

The onomasticon is a collection of proper names of persons, works, and places in the history of Jainism. Klatt wrote this work on his own, which must have been an almost unmanageable task given the fast-growing amount of available data by the end of the 19th century. Klatt's principal sources are the reports on the search for Sanskrit and Prakrit manuscripts in India as well as manuscript catalogues, such as the surveys by A. Weber, R.G. Bhandarkar, P. Peterson, G. Bühler, and R. Mitra. In addition, he used all primary and secondary sources that he could find, including textual, epigraphical, and bibliographical sources. In addition to the material that was available to him at the library in Berlin, he also consulted manuscript collections in other places, such as Florence and Vienna. The fact that Klatt even used his family holidays to conduct research at these places illustrates his extraordinary dedication to his project. The result of his efforts is a 5,338 page manuscript with c. 15,000 entries.

Unfortunately, Klatt's career ended prematurely by the time that he laid the last hand on his work due to mental illness, which explains why the manuscript was never published. Nevertheless, the work was never completely forgotten and some people were aware of the value of the onomasticon. For example, Walther Schubring praised Klatt's opus magnum as one of the principal accomplishments of 19th-century Jaina research. One may wonder, however, how useful the onomasticon can be after more than a century. In general, the entries are still highly useful for scholars in the field of Jaina studies. There is no alternative work that contains as many references to Jaina manuscripts and inscriptions as Klatt's volume. Nevertheless, the Onomasticon should be used with care. After all, when Klatt compiled his work, Jaina studies was still in its infancy and the general understanding of the history of Jainism was limited. For example, the entry on the Tattvārthasūtra identifies the work as a Digambara text while it is far from clear whether the presupposed sectarian division already existed at the time of the composition of the Tattvārthasūtra, and few contemporary scholars would agree with Klatt's label.

Yet, these little shortcomings are largely compensated by the richness of information in Klatt's entries. Moreover, the editors of the onomasticon have managed to make the work even more useful than the original manuscript in several ways. First, the introductory analysis of Klatt's sources and method clarifies the scope and limitation of the work. Second, the present edition contains a reconstructed bibliography, prepared by Krümpelmann. This overview not only guides the reader to the right sources but it also offers a unique insight into the state of knowledge among leading Indologists in the 19th century. It must be said that the relatively high price and the huge format of the book might somewhat hinder the wide distribution of the volume. In its present form, the book is ideal to be consulted at a library, but it probably won't end up on the desks of all possible users. It would be a major help for the field of Jaina studies if the data in the onomasticon would be a provided online in a searchable database.

To conclude, as the first volume in Harrassowitz’s new series on Jaina studies, this book is a milestone in the academic study of the Jaina tradition. The Jaina-Onomasticon is a highly useful publication for scholars working on the literary and religious history of the Jaina tradition, while the general introduction and the reconstructed bibliography will be of interest to anyone with an interest in the disciplinary history of South Asian studies and Jaina studies in particular.