In De partibus animalium A1, Aristotle presents —in a darker than usual way— decisive details of the methodology he devised for his science of nature. His indications seem to point the path along which Aristotelian biology should travel. However, numerous textual and systematic difficulties have given rise to a number of conflicting interpretations, in the context of a vigorous stream of philosophical research and debate since the last third of the last century. In this stream of studies, Michael of Ephesus’s (...) commentary on PA and his views on the subject remain relatively ignored. A complex multiplicity of factors seems to support the lack of sufficient consensus among leading contemporary specialists to explicitly consider those contributions. The purpose of this paper is to examine several of these factors and, based on the evidence provided by little explored aspects of Michael’s texts, to offer arguments in favor of that consensus against a number of alternatives. I shall argue that the contributions of this late commentator deserve to be considered —mutatis mutandis— as seriously as it is done with the main ancient Greek commentaries; in particular, in the philosophical studies of those who are currently interested in that methodology or are engaged in Aristotelian biology. (shrink)