booK reVIeWS AND NotICeS466 EINAR DUENGER BOHN IFIKK, University of Oslo Andrew Schumann (ed.) Logic in Religious Discourse. Ontos Verlag, 2010. Logic in Religious Discourse contains twelve more or less historical essays by twelve different authors on more or less formal reasoning in connection with various forms of religious thought. The essays cover reasoning in strands of Indian, Chinese, Jewish and Christian thought, as well as mysticism. The book also contains a preface by the editor. According to the editor, religious logic is to be understood as a distinctive branch of modern logic, and the book is intended as a first step towards a holistic understanding of such a branch of logic independent of any particular religious school of thought. This is an interesting and ambitious goal, and one that I for one support. maybe religious reasoning is something different from ordinary (non-religious) reasoning, and as such merits its own logical studies. If so, religious logic should indeed be thought of as a branch of its own within the logical study of reasoning. If not, it is still an interesting topic as to why it is not, and as such it still might merit a study of its own. unfortunately, this ambitious goal is a goal that the book, as far as I can see, fails to fulfill. In what follows, I first provide three critical sets of comments as to why that is. I secondly summarize what these sets of comments indicate about the book as a whole. I end by pointing out what I take to be the most interesting parts of the book, and why. First, being a non-expert on non-western philosophy and religious thought, I was, with the exception of Schang's 'A Plea for epistemic truth', able to make little sense or interest out of the first five essays. This might of course be just a fault of my own, but it might also, arguably, be a fault of a book that intends to provide the first steps towards a holistic understanding of religious logic independent of any particular religious school of thought. It is also not clear, at least not to anyone not already entrenched in the relevant history of Indian and Chinese thought, what these essays have to do with religious logic, or logic in religious thought and discourse as such. (In fact, with respect to the first two essays by Kak and bhattacharya, it is not even clear what these essays have to do booK reVIeWS AND NotICeS 467 with logic as such. After all, there is there no real attempt to formalize anything.) Second, perhaps with the exceptions of Schang's essay 'A Plea for epistemic truth' and uckelman's essay 'reasoning about the trinity', none of the essays engage to any sufficient degree with developments in contemporary logic. This wouldn't be a problem if the book weren't intended to be providing the first step towards a holistic understanding of religious logic as a distinctive branch of modern logic, but it is. For example, anyone with some knowledge of contemporary non-classical logic, most significantly many-valued logics, will find little of logical shock-value in this book where negation is a central topic (cf. G. Priest, An Introduction to Non-Classical Logic, Cambridge: Cambridge university Press, 2001, Chapter 7). It is common ground in contemporary non-classical logics that negation is a puzzling phenomenon, e.g. in intuitionistic logic and many-valued logics the negation of a negated formula (~~F) is not necessarily equivalent to the un-negated formula (F). but this lack of engagement with contemporary logic should make one wonder what the real value of the book is. Is it just an exposition of some scattered issues of logic with respect to some historical sources? If so, why are Islamic schools of thought left out? Why are African schools of thought left out? If so, I am also not sure the book merits its title. Third, perhaps with the exceptions of Schang's essay 'A Plea for epistemic truth' and uckelman's essay 'reasoning about the trinity', none of the essays go critically into much depth with respect to the logical issues they discuss. to take just one example from what is in fact one of the more interesting essays in the book, namely Dvorák's 'Analogy in Thomism': why isn't there any discussion of how reasoning by analogy relates to reasoning by disjunction? There seems to be interesting links. Also, there isn't much critical examination of whether the various logical structures discussed are any good. The book is mostly descriptive. After having read the book one is thus left with the impression that one has been given a mere exposition of some historical sources, but without much critical discussion, and without much as to the background motivation. This lack of critical examination should leave one, both as a philosopher and as a logician, unsatisfied, especially if the goal is to provide one with the first step towards a holistic understanding of religious logic as a distinctive branch of modern logic. booK reVIeWS AND NotICeS468 taking these three sets of comments together, I believe the overall problem with the book is the following: it is unclear whether it is purely historical and expository, in which case it's preface is misleading and the book looses much interest due to an inadequate engagement with the original texts, or whether it is also engaging with modern logic as such, in which case the book is too superficial, uncritical and lacking in many other ways due to its inadequate engagement with modern and contemporary logic. With that being said, let me end by pointing out what I believe are the best parts of the book, and why. With respect to logical details and depth, Fabien Schang's contribution 'A Plea for epistemic truth' and Sara uckelman's contribution 'reasoning about the trinity' are by far the best. In Schang's essay we are provided with the beginnings of a seven-valued logic, a rationale for why it is seven-valued (and not some other number), and some interesting links with more contemporary logics developed by Kleene (K3) and Priest (lP). In uckelman's essay we are provided with a supposedly sound logic for syllogistic reasoning about the trinity, which I found both interesting and original. We are also here provided with some genuine motivation for the system, e.g. how to solve the paradoxes by being clear on the different notions of identity involved. uckelman's contribution is a true contribution to religious logic as such, though I would have liked to see a more critical discussion of the three notions of identity involved. Can we really understand all three notions as notions of identity and distinctness proper? I would also have liked to see more on how her system of syllogistic reasoning about the trinity relates to (and perhaps solves some problems with) contemporary debates on the trinity in relation to classical first-order predicate logic. (We are promised more details in her dissertation of 2009. I have not gone to look whether the promises are fulfilled.) With respect to religious thought, I found Petr Dvorák's 'Analogy in Thomism' and Pawel rojek's 'towards a logic of Negative Theology' the most interesting, though I would have liked to see more of the logical details entailed by the pictures discussed. What would a suitably full logical system look like for each one of them? Could there really be such a system? It is hard to say without more details. booK reVIeWS AND NotICeS 469 I also enjoyed timothy Knepper's essay 'Ineffability Performance' on mysticism, which aims to clear some ground for further work on mysticism along the lines of Sells (Mystical Languages of Unsaying. Chicago: The university of Chicago Press, 1994). The essay goes a long way towards critically clarifying what seemingly cannot be clear, namely what cannot be said. This essay might in fact be interesting for purposes of the philosophy of language at large. All in all, Schumann's Logic in Religious Discourse is an ambitious book with some interesting individual contributions, but fails in its purpose due to an unclear target, I believe.