Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Professor Henrik Lagerlund


My dissertation focuses on what I call Aristotle’s “problem of katholou ” in order to distinguish it from the “problem of universals” which is traditionally framed as the problem about the ontological status of universals. Aristotle coins the term katholou (traditionally translated as “universal”) and defines it as “that which is by nature predicated of many things". Yet, the traditional focus on the ontological status of universals is not Aristotle’s. His positive remarks about universals remain neutral with regard to their ontological status and escape the standard divide of realism and nominalism. I start with Aristotle’s neutrality and focus on the problem he is concerned with, namely, the problem of katholou.

This problem is to explain how what is most real can also be most knowable. It is generated by two of Aristotle’s philosophical commitments: (i) particulars are most real and (ii) universals are most knowable (since knowledge is of the universal). These commitments are supposed to lead to what is traditionally called a discrepancy between the real and the knowable, and many authors think that it constitutes the most serious, perhaps insoluble, problem in Aristotle's philosophy. I believe it is soluble, but I do not assume that there must be only one solution. My main task is to show that Aristotle’s writings reveal three related solutions to the problem: one that appeals to the ontological interdependence between universals and particulars; one that appeals to the corresponding epistemological interdependence (and to notions of potentiality and actuality); and one that invokes the concept of form. In the last chapter of the dissertation, I show that Aristotle’s commentator, Alexander of Aphrodisias, adopted primarily the last solution, which appeals to forms. I suggest that Alexander deeply influenced the future direction of the discussions of both Aristotle’s problem of katholou" and the traditional problem of universals.