- John Buridan
This is a marvelous book, a “must read’ for anyone interested in understanding the philosophical debates of the later Middle Ages and a useful book for contemporary philosophers who will find in it a sophisticated articulation of a philosophical position well able to provide perspective on a number of contemporary debates. It is exceptionally well-written, clear, and insightful.
We are now in a fairly good position to understand Buridan’s role in later medieval philosophy, his general philosophical orientation, and the milieu in which he worked. What we have lacked is a detailed study of the core of his philosophy, and it is this gap that Gyula Klima’s book splendidly fills—just as our picture of Buridan’s thought is coming into focus. Much of Buridan’s work is either unedited or exists only in incunabula, and there are underway editing projects of central texts that will shed considerable new light on the man and his work. We are fortunate, however, to have already a splendid English translation of and commentary on Buridan’s massive and rich Summulae de dialectica by Klima himself, and this, together with incunabula and with recent editions of some of his other logical works, forms a sufficient basis of text for reasonable confidence that Klima’s study will stand the test of time.
John Buridan focuses on the philosophy of thought and language, metaphysics, and parts of the epistemology of science. Buridan has much to say about action theory, economics, ethics, politics, natural philosophy, and psychology—to mention only a few areas not covered in this book that have been the subjects of recent particular studies—but because in all of these areas his thought is shaped by his thinking about language, thought, and what there is, Klima’s focus is appropriate. Klima sees Buridan as central to the late medieval nominalist tradition, but nonetheless as located in a conceptual space between Ockham and Aquinas. From Ockham derive the central features of his metaphysics and philosophy [End Page 100] of language, while Aquinas is important for his epistemology. Buridan is, withal, a strikingly independent thinker.
Chapters 3–5 of the book (making up some forty percent of the total) are devoted to the issues raised by Buridan’s development of his mental language hypothesis and the account of concept formation it involves. Concept formation begins when objects are as if “in our prospect” (in prospectu nostro). Klima understands this as a matter of objects being as if located in a particular fully determinate spatio-temporal context and so being presented as singular. He argues that, for Buridan, our sensory contact with the world is information rich. We do not (typically) sense mere whiteness or heat, but white or hot things, and while our senses can respond only to the whiteness or the heat, our intellects respond also to the things themselves. Thus, Klima argues, Buridan is able to account for substantial concepts and avoid the line of thought that led some British empiricists to identify things with congeries of features. Klima reads Ockham as holding that general concepts signify what they do in virtue of a sui generis similarity between the concept and its significata, and that singular concepts add to this an actual causal link whereby the singular object signified gives rise to the concept, whereas Buridan locates singularity in the way in which the object is presented—as in prospectu.
Klima argues that, while Buridan permits singular concepts only of what is in prospectu, he allows spoken and written proper names for things which are not; when, for example, we intend to use a spoken word as others use it—and so to signify their concept. This already suggests the complexity of the relations between spoken and mental language, and Klima’s discussion of these relations is one highlight of the book.
The possibility that God might deceive us was a live one in Buridan’s milieu. Klima argues (chs. 11 and 12) that within what he calls the pre-modern epistemology of Aquinas and...