Quel savoir après le scepticisme? Plotin et ses prédécesseurs sur la connaissance de soi (review)

In this closely argued monograph, the author examines one chapter of Plotinus’s treatise V.3 [49], titled “On the Knowing Hypostasis and That Which is Beyond.” In the fifth chapter of that work, Plotinus makes the case for asserting that knowledge is primarily or essentially self-knowledge. This is certainly not a novel claim in the history of ancient philosophy, as Kühn amply demonstrates. It is a central claim in Aristotle’s epistemology and the later Peripatetic tradition. What is of particular interest for the Plotinian account of knowledge as self-knowledge is that it is made in response to a skeptical argument found in Sextus Empiricus, although it is likely that it did not originate with him. That argument attempts to pose the following dilemma for any “dogmatist” who embraces self-knowledge. Either this self-knowledge is in effect one “part” of the knower knowing another “part,” or else it is one “part” knowing not another “part,” but rather knowing “itself.” The first horn of the dilemma means that self-knowledge is not knowledge at all, since the putative knower would have to be able to show that the first “part” is representing the second part accurately. And this is something that cannot be done without the first “part” knowing the second “part,” not by representing it, but by being identical with it. This leads to the second horn: if the knowing “part” just knows itself and not an object different from itself, then this knowledge will have no content. So, self-knowledge seems to be impossible. All this the author explains with great care, though he does not emphasize a point that seems to me important, namely, that Sextus, like Plotinus and like Aristotle, is assuming that knowledge, as propounded by all dogmatists, is primarily taken to be self-knowledge, in which case the skeptical attack on the latter becomes all the more serious and justifies Plotinus’s extensive response to it. The reason for this is that apparently only self-knowledge could be infallible, and it is infallibility that characterizes knowledge apart from mere belief.

The main part of this book (45–311) is devoted to the structure of the argument in V.3, 5. Along the way, Kühn keeps in focus the historical discussions about knowledge that were the immediate background for Plotinus’s reflections. The last part of the book (313–416) provides a substantial exegesis and interpretation of Aristotle’s account of divine and human self-knowledge, of Alexander of Aphrodisias’s commentary on this account, and on Academic and Stoic epistemological contributions. Kühn argues, against many scholars, that Plotinus’s doctrine of self-knowledge is innovative in claiming that it is an activity and not a relation between a subject and an object. Against the obvious objection that Aristotle, too, conceives of the self-knowledge of the divine as an activity, the author argues that Plotinus relies on Plato’s Sophist in maintaining that the activity of the self-knowing Intellect is in fact that of the intelligible object, that is, the Form. Thus, Kühn is led to find in Plotinus an equivocation in the use of the Greek term for “knowledge,” that is, when applied to the subject for which knowing implies an intentional object, and for the object, for which knowing is a purely immanent activity without such an object.

The great strength of this book is its minute attention to every nuance of Plotinus’s text and its aim—largely met—to provide a perspicuous and accurate presentation of the argument. All the relevant scholarship is treated in the footnotes, and all the relevant texts from elsewhere in the Enneads are discussed in their context. The principal weakness of the book is found in the author’s choice to set aside all metaphysical...