Journal of the History of Philosophy

This remarkable book provides a comprehensive account of the theory of knowledge of John Buridan (c. 1300–61), who, along with William of Ockham, was the fourteenth-century thinker who had the greatest influence on philosophical posterity. Buridan’s contributions were many, through his logical masterpiece, the Summulae de dialectica, and multiple commentaries on nearly every work in the Aristotelian corpus. But his signal contribution was to re-orient the philosophical enterprise along secular lines as an autonomous discipline, no longer “handmaiden” to theology. He achieved this not by publishing revolutionary manifestos or crossing swords with Church authorities; rather, over the course of his long career in the Faculty of Arts at the University of Paris (where he remained a teaching Master, apparently choosing not to move on to doctoral studies in a higher faculty such as theology, as was typical for academics of the time), he subtly changed the way philosophy was done by reformulating the range and order of questions falling under the purview of philosophy, as well as the arguments used in replying to them.

Biard’s account builds on the core Buridanian concept of scientia—the Latin term for Aristotle’s ‘epistēmē,’ or “body of knowledge,” too-narrowly rendered in English as ‘science.’ More broadly, he holds that scientia is “a central term for fourteenth-century philosophy, globally redefining the cognitive relation of the human intellect to the world in its linguistic, logical, and psychological aspects” (11). For thinkers like Buridan, scientia articulates mental dispositions in a language which “must constantly be addressed under a two-fold aspect: semantic (it must in the final analysis relate to the natural and human world) and argumentative (it deploys certain forms of reasoning, of which demonstration propter quid is the highest form)” (12). Buridan’s method places concepts, words, and things in distinct but mutually conditioned orders, employing the proto-epistemic notions of evidentness (evidentia) and certitude (certitudo) as a kind of bridge between them. This has some interesting results. For example, Buridan argues that the proper object of scientific knowledge must be two-fold, that is, both propositions and things signified, contra the more radical position of Ockham (for whom propositions alone are the object of science) and defenders of the complexe significabile like Gregory of Rimini (111). But Buridan also uses the controversy over the skeptical and anti-Aristotelian arguments of Nicholas of Autrecourt to develop the idea that evidentness and certitude come in degrees, which he also systematizes relative to the aforementioned orders. Because scientific knowledge is based on the assumption that the common course of nature holds, the possibility of divine intervention in the natural order can be set aside and our assent calibrated instead to the (still compelling) testimony of sense, memory, and experience. As Buridan often says, “this evidentness suffices for natural science—which is why it is absurd to reject the natural sciences because there is no absolutely perfect evidentness concerning them” (Quaest. de Gen. et Corr. I.6; quoted at 33 n. 2).

The book is very clearly written, and Biard’s exegesis is absolutely sound throughout, with all of his readings supported by quotations from the relevant texts. He is also literate with the philosophical milieu of the first half of the fourteenth century, remarking on contemporary influences when appropriate and refusing to speculate where our evidential base remains thin, as in the case of Ockham’s influence on Paris Arts Masters. [End Page 786]

My quibbles are few. On the minor side is the absence of an index of quotations from Buridan, which makes it difficult to make full use of Biard’s impressive command of the primary sources. More substantive is Biard’s tendency merely to reference recent interpretations on controversial topics rather than join in the controversy—which, I suppose, is to be expected in a piece of exegetical scholarship. But there are places where I wish the consequences...