- The Science of the Soul. The Commentary Tradition on Aristotle’s De anima, c. 1260–c. 1360 by Sander W. de Boer
This book, a revision of the author’s doctoral dissertation, traces the history of several disputes concerning Aristotle’s De anima in the late thirteenth and early fourteenth centuries. The stated aim of the work is to demonstrate that the philosophical study of soul “transformed” during this period, with Scholastic philosophers becoming increasingly pessimistic [End Page 168] of the possibility of establishing the nature of the human intellective soul by natural reason alone. This pessimism took hold despite a continuing consensus that the nature of non-human vegetative and sensitive souls could be understood by reason alone, thus resulting in a deep division between the study of human souls and that of non-human souls.
De Boer’s study is distinguished from much of the existing secondary literature in two ways. The work’s first distinctive feature is its focus on disputes concerning the Aristotelian conception of soul in general, rather than of the intellective soul in particular; consideration of vegetative and sensitive souls is featured more here than in some other studies. The disputes covered center on two sets of questions. In the lengthy third chapter, De Boer discusses a number of questions concerning the methodology of the science of the soul, including (i) whether this science belongs to metaphysics or natural philosophy, (ii) whether the subject of this science is the soul itself or the animated body, and (iii) how the apparent difficulty of this science impacts the epistemic status of its conclusions.
Then, in chapters 4 and 5, De Boer covers disputes about the adequacy of Aristotle’s definition of soul and about the distinction between souls and their powers. One of the issues scrutinized here is the question of how Aristotle’s definition of soul (as “the first actuality of a natural body which has life potentially”) can be harmonized with the rejection of a plurality of substantial forms, a position that became increasingly common during this period. On a view such as Aquinas’s, for instance, the soul is the only substantial form of a living substance, and thus all of a living substance’s actuality derives from its soul. But given this, it is difficult to see how the soul can be the actuality of “a natural body which has life potentially.” A body that has life only potentially would be a body without a soul (for a body with a soul is one that has life actually, not merely potentially); but to hold that all a living substance’s actuality derives from its soul is to deny that there could be such a thing as an organic body without a soul.
The second distinctive feature of De Boer’s study is that he focuses solely on commentaries on the De anima, setting aside discussions of soul that take place in other texts (for example, in commentaries on Peter Lombard’s Sentences). This results in a somewhat unorthodox assortment of figures being studied. Indeed, with only two or three exceptions, the philosophers studied here will be unfamiliar even to many specialists: Thomas Aquinas, Radulphus Brito, John of Jandun, John Buridan, Nicholas Oresme, and the authors of five anonymous De anima commentaries.
De Boer’s choice to focus on these commentaries is somewhat curious. He admits that his selection was guided by the availability of these particular works in either a renaissance or modern edition (10n22); overlooking the many De anima commentaries available only in manuscript is understandable though regrettable. Yet there are still a number of edited commentaries from the period that are largely or entirely ignored, including those of Siger of Brabant, Giles of Rome, John Duns Scotus, Walter Burley, and Albert of Saxony. Scotus’s short quaestio commentary is set aside for not discussing the methodological issues De Boer focuses on (11...