Possibility and Necessity in the Time of Peter Abelard by Irene Binini (review)

Abstract

text is so rich and complex. A simple but careful look at this map confirms what Strobino makes clear and insists upon: Avicenna greatly develops, enriches, completes, and even outgrows some of Aristotle’s views. The Book of Demonstration is far more than a commentary on the Posterior Analytics ; it is a complete reworking of it. Strobino shows that Avicenna grounds his theory of demonstration and science on two basic notions—conception (tasawwur) and assertion (tasdı̄q, which some other scholars translate as “assent”)—and so gives a unified approach to his theory. Scientific conceptions require better understanding of definition and description. Avicenna builds definitions and descriptions on essentialism and, therefore, grounds them in metaphysics. As for scientific assertions, in contradistinction to nonscientific ones, they must be necessary and give the cause. Therefore, Avicenna places great importance on modality and develops modal syllogisms, whereas Aristotle focused on categorical syllogisms and neglected hypothetical and disjunctive syllogisms. Avicenna also elaborates a sophisticated account of modality and its metaphysical implications. Furthermore, he broadens and enriches the appreciation of causality and explanation. These developments, according to Strobino, lead Avicenna to set forth an intricate division and hierarchy of the sciences under metaphysics, which provides their ultimate principles and allows for a unified understanding of the sciences while respecting their particularities. According to Strobino, Avicenna is keen to develop a theory of science that gives a good account of science as it is practiced. Strobino carefully shows how Avicenna’s theory better reflects this practice than does Aristotle’s. Strobino does not simply highlight how much Avicenna distances himself from Aristotle and goes far beyond what the Posterior Analytics yields, but also shows how much Avicenna relies on points adumbrated by his predecessor al-Fārābı̄ in his own Book of Demonstration. The way Strobino through his analysis of demonstration links Avicenna’s understanding of logic, epistemology, and metaphysics underscores the coherence and unity of Avicenna’s philosophy. Scholars were aware of the importance of demonstration for Avicenna in various philosophical fields, but until the release of this book, they seemed not to have fully grasped the centrality and essential role played by the Avicennian understanding and focus on demonstration. Of course, Strobino does not limit himself to an analysis of passages in the Book of Demonstration. He has an encompassing knowledge of Avicenna’s texts and uses them well to flesh out and enrich what remains terse in the Book of Demonstration. He even takes into account the way one of his successors, al-Tūsı̄, reads him. He also shows an extensive and wide-ranging knowledge of Aristotle’s texts and of Aristotelian scholarship, as well as an interest in the Greek commentators and Galen and their relevance for interpreting Avicenna. Avicenna’s Theory of Science is not an easy book to read, as it is often very technical, particularly when dealing with purely logical points or issues, but reading it is rewarding if one does so slowly and meditatively. The author, in fact, illuminates difficult matters but does not waste words. From now on, any serious work on Avicenna will require taking this book into account. Furthermore, this book explains why in the East after Avicenna philosophers no longer reflect much on Aristotle’s Posterior Analytics but rather comment on Avicenna’s Book of Demonstration or debate with it. T h é r è s e A n n e D r u a r t The Catholic University of America