Abstract

The categories of acting and undergoing are not really examined in the Aristotelian treatise. This article aims at showing how the anonymous author of the Book of six principles analyses them in trying to fill this void. By doing so, the article underlines how this analysis philosophically relates to some technical problems discussed in the neo-platonician exegetic tradition of Aristotle’s Categories. It makes reference to some thir-teenth- and fourteenth- century commentaries on the Book of six principles both to present how this text was interpretated and to give a glance at how the conceptions of these two categories came to evolve.