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

This book is an impressive work written by a young Italian scholar who received her PhD only five years ago in Pisa. It is divided into three parts. Part 1 gives a survey of "Early 12th-Century Debates on Modal Propositions"; part 2 is devoted to "Abelard's Modal Logic"; part 3 deals with the views of "Abelard on the Metaphysics and Epistemology of Modalities." The author displays a profound knowledge of the relevant literature. The primary sources comprise twenty manuscripts preserved in various European libraries, plus forty-eight printed works (from Abelard to William of Sherwood). The list of secondary sources contains altogether 136 items from A (Astroh) to Z (Zagzebski), but, interestingly, it does not mention a monograph that, by its very title, claims to give an exposition of Abelard's logic, namely Maria Teresa Beonio-Brocchieri Fumagalli's La Logica di Abelardo (Firenze: La Nuova Italia, 1964).

As far as I can judge (as a nonnative English-speaker), the linguistic quality of Binini's book is quite good. The explanations in the main text, including the translations from Latin sources, are easily comprehensible, and the many quotations (distributed over no less than 655 footnotes) are almost without any fault. Thus, the book rightly deserves inclusion in the prestigious series Investigating Medieval Philosophy. Yet, at least according to my taste, the book contains many redundancies. Again and again, the author first explains a certain issue at some length, then confirms the correctness of her interpretation by means of a longer (English) quotation, and finally reconfirms it by fully quoting the Latin text in the footnotes.

As Binini explains in the book's concluding chapter, her aim is to present "an all-encompassing reflection on [Abelard's] works on modalities" and "a comparison between these works and the parallel reflections advanced by other masters and logicians in the early 12th century" (308). She undoubtedly achieves this goal. The comparison of Abelard's views on possibility and necessity with the views of other logicians is mainly carried out in chapters 1–3. Ancient and early medieval logicians such as, in particular, the Stoics and Boethius favored the basic idea that "something," p, is necessary if and only if p is always the case (or true). Accordingly, p is possible if and only if p is at least sometime the case. Abelard, however, was not willing to accept that each possibility has to become realized at some time. He instead offered a "nature-based characterization of possibility" that can "account for unrealized, past, counterfactual, and even unactualizable possibilities" (308). Abelard's idea is that something, x, is possibly a P if and only if the property of being P is compatible with the nature of x. Hence this view basically amounts to a de re conception of possibility that attributes modalities to things, while the temporal view attributes modal properties primarily to propositions (or states of affairs) and hence can be labeled de dicto (or de sensu).

Let us now turn to Binini's twofold aim (as formulated on the back cover of her book) to present a "uniform and consistent" reassessment of Abelard's theory of modalities and of his modal logic. The former task is tackled in chapters 8–10. After summarizing, in chapter 8, Abelard's general views on "Nature and Modalities," chapter 9 is devoted to a detailed discussion of the "Many Senses of Possibility." In five consecutive sections, Binini investigates the conception of (1) possibility as "non-repugnancy with nature" (illustrated by the thesis that "any man can be a bishop" [235]); (2) unrealizable but "conceivable" possibilities (such as the existence of humans lacking the ability to laugh [240]); (3) determinate potencies (like that of an amputee who nevertheless "can walk" [248]); (4) past and counterfactual potencies (like that of a blind person who might be able to see); and (5) other puzzling de re possibilities (such as "irrational humans" [261]).

The final...