Abstract

This is a wonderful book. It is, in my opinion, the best book on Aristotle’s treatment of the physical world to appear in recent years. Still, this book is not one that can be read through on a Sunday afternoon. It resembles a text of Aristotle in the compactness of argument, though not, I am happy to report, in clarity. Like a guide raised in the wild, Lang leads us through a large sector of the forest of arguments in the Physics and De Caelo. This analogy brings me to the following point: Lang’s perspective on Aristotle is extraordinary. Lang is the author of another excellent book, Aristotle’s Physics and Its Medieval Varieties. Discussions of Aristotle’s philosophy of nature through the lens of medieval philosophy and science are not uncommon. These discussions, however, face the peril of attributing, in one way or another, viewpoints to Aristotle that are actually those of his medieval successors. For this reason most work on Aristotle is now done without reference to medieval thought. Perhaps this is as it should be. But one of the great difficulties in understanding Aristotle’s conception of the world is how we are to interpret what he says. Our perspective on the world is largely formed on the basis of early modern rejections of medieval Aristotelian views. That is to say that built into our perspective is a negative response not to Aristotle directly but to medieval interpretation of Aristotle. This fact makes it extremely difficult for us to see Aristotle clearly. Here lies the advantage of knowing the “medieval varieties” of Aristotle’s natural philosophy when we try to make sense of Aristotle. Knowing this helps us distinguish more clearly between our own perspective and its roots and Aristotle’s. Aristotle’s perspective is in fact fundamentally different from ours. For example, Lang points out that to insert the notion of “speed” into Aristotle’s discussion of motion is “seriously misleading” because speed is conceptually distinguishable from moving bodies and is so treated, whereas motion, for Aristotle, is always the actualization of a capacity intrinsic to a moved body; therefore motion can neither be quantified nor abstracted from what is moved.