In recent years, publishers have flooded the academic market with introductions, guides, commentaries and companions to philosophers and their works. Many have been devoted to Kant and many are of very high quality. The Continuum Companion to Kant stands out from this crowd, because of its organization and the quality of its contents. These differ significantly enough from other available companions to make The Continuum Companion to Kant a valuable contribution to the scholarship. However, a series of omissions and oversights detracts from the usefulness of The Continuum Companion to Kant as a source, reference and guide.

The Continuum Companion to Kant is a lexicon, much like Eisler's Kant-Lexikon (1930), Caygill's Kant Dictionary (1995) and Holzhey and Mudroch's Historical Dictionary of Kant and Kantianism (2005). This distinguishes it from the more established Cambridge Companion series, as well as certain other volumes in the Continuum Companion series. In Brandon Look's The Continuum Companion to Leibniz (2011), for example, we find a series of seventeen articles dealing with Leibniz's philosophy, the historical context of his thought and the reception of his work, written by established and respected scholars. Each article treats its subject with a combination of breadth and depth that is difficult to achieve in a lexicon entry. This does not mean there is no value in a lexicon; lexicons contain more entries than other kinds of companions and they are more accessible to those who might not know where to begin with other kinds of companions. Yet The Continuum Companion to Kant will soon be dwarfed by the 2,100 pages of the Kant-Lexikon to be published by Walter de Gruyter. And, at $190.00, it is not clear that it will be more accessible to the undergraduates, graduate students and non-specialists that would find such a lexicon most useful.

The first part of the Continuum Companion deals with Kant's key writings. Here we find short entries on Kant's major works, written by Gary Banham and arranged chronologically. One of the really nice things about these entries is that Banham reconstructs Kant's works section by section, giving readers a sense of the structure of Kant's works, as well as their contents. Unfortunately, there are no entries for many of Kant's works, which are not mentioned anywhere in this section. Banham treats the pre-Critical period in a particularly cursory manner. The Only Possible Argument in Support of a Demonstration of the Existence of God (1763) and the inaugural dissertation On the Form and Principles of the Sensible and the Intelligible World (1770) are the only pre-Critical works for which there are entries. The New Elucidation (1755) is briefly mentioned at the beginning of the entry on The Only Possible Argument, but other pre-Critical works such as Thoughts on the Estimation of the Living Forces (1746), Physical Monadology (1756), Inquiry Concerning the Distinctness of the Principles of Natural Theology and Morality (1764), Observations on the Feeling of the Beautiful and the Sublime (1764) and Dreams of a Spirit-Seer (1766) are not mentioned at all in this section. It may be debatable whether these are really key works; yet the attention they have received in the scholarly literature suggests they are. Undergraduates, graduate students and non-specialists hoping to find entries on these works will be surprised not to find them in The Continuum Companion to Kant.

The second part is divided into chapters on ‘Philosophical and Historical Context’ and ‘Sources and Influences’. The reason for this division is difficult to discern. Entries on Lambert and Mendelssohn are included in the ‘Philosophical and Historical Context’ chapter, while entries on Tetens and Herz are included in the ‘Sources and Influences’ chapter. This is unfortunate, because readers will have to look in more than one place for entries on Kant's contemporaries and correspondents. It would be better, I think, to avoid these confusions by eliminating the division between these two chapters in future editions of the book. In some cases, the assimilation of these chapters could be extended to the entries themselves. The entry on Aristotelianism in the section on ‘Philosophical and Historical Context’ could easily be incorporated into the entry on Aristotle in the ‘Sources and Influences’ section. Perhaps that would make room for an entry on rationalism to complement the entry on empiricism in the ‘Philosophical and Historical Context’ chapter.

Part 3 addresses a series of key themes and topics in Kant's philosophy. Some of the entries in this section are helpful, while others suffer from the incompleteness and disorganization that marred the two previous sections. For example, the entry on the a priori/a posteriori distinction mentions the distinction between pure and empirical cognition, but does not mention the difference between the pure forms of intuition and the pure concepts of the understanding, leaving the reader with the impression that the a priori/a posteriori distinction applies only to knowledge, when Kant also says that the elements of cognition can be pure or empirical, a priori or a posteriori (A50–1/B74–5). The entry on critique also suggests the term refers to the negative evaluation of the state of metaphysics in Kant's time, rather than the ‘critique of the faculty of human reason’ that Kant uses to determine ‘the possibility or impossibility of a metaphysics in general, and the determination of its sources, as well as its extent and boundaries, all, however, from principles’ (Axii). Instead of citing the passage from the Preface to the second (B) edition of the Critique of Pure Reason, where Kant criticizes Wolff for failing to begin his metaphysics with ‘a critique of the organ, namely pure reason itself’ that makes metaphysics possible (Bxxxvi–xxxvii), the author of the entry goes on to talk about distinctions between representations and objects, matter and form, phenomena and noumena. These distinctions are certainly the products of Kant's critique, but without a clear explanation of what Kant meant by the term, it is difficult to see why and how these distinctions follow from a critique of pure reason, if a critique of pure reason is just the way Kant dismisses rival theories. Both of these entries – on the a priori/a posteriori distinction and on critique – suffer from the restrictions the lexicon format imposes.

The entries on the reception of Kant's thought in part 4 are, in my view, superior to the ones in the preceding sections. They are accessible to readers who would find a lexicon most useful and combine breadth, depth and systematic exposition in a way that other sections of the book do not. The entries on the reception of Kant's inaugural dissertation (by Corey Dyck), early responses to the Critique of Pure Reason (by Richard Fincham), the reception of the Critical philosophy in the 1790s (by Ernst-Otto Onnasch), Hegel's appropriation of Kant's theoretical philosophy (by Johan de Jong), Neo-Kantianism (by Christian Krijnen), Heidegger (by Karin de Boer), and analytical Kantianism (by Christian Onof) are all detailed and informative, but the entries by Onnasch and Krinjen are perhaps the most impressive. Onnasch's entry on the reception of the Critical philosophy in the 1790s goes beyond the familiar story about the Pantheismusstreit, taking into account some of Dieter Henrich's studies of Kantianism in the Tübinger Stift and complicating the short version of the ‘from Kant to Hegel’ story that is found in many accounts of the history of German idealism. The quality of Krijnen's entry on Neo-Kantianism also indicates that this movement is finding its place in the history of modern philosophy and is beginning to be appreciated as a something other than a foil for positivism and phenomenology.

The extensive, 50-page bibliography in part 5 and the comprehensive, 11-page index at the end of the volume enormously increase its value as a scholarly reference. Given the unfortunate division of part 2 and the lack of integration and completeness in part 3, I would recommend that readers begin with the index and work backwards to find the entries they are looking for. Using the index, readers should be able to find discussions of works that are not included in the key works (like New Elucidation, Inquiry, Observations and Dreams of a Spirit-Seer), figures that might be considered either ‘Philosophical and Historical Context’ or ‘Sources and Influences’ (like Wolff and Mendelssohn), and concepts that might be addressed under different headings in the key concepts section (like ‘empirical’ or ‘practical reason’). Then, having found the entries they are looking for, they can turn to the bibliography and find ways to continue their research. The bibliography is divided into nine sections: (1) Kant's works in German; (2) English translations; (3) Biographies of Kant; (4) Introductions to Kant; (5) Edited Collections on Kant; (6) Context and Reception of Kant's Work; (7) Kant's Theoretical Philosophy; (8) Kant's Practical Philosophy; (9) Kant's Third Critique, Aesthetics and Teleology. This will be helpful for undergraduates, graduate students, and non-specialists as they try to find their way through the voluminous scholarly literature on Kant.

Despite its shortcomings, The Continuum Companion to Kant has much to offer. I am sure it will find a place in academic libraries, where it will be consulted by students and scholars.