Our usual method" is an expression that Aristotle uses in a passage of the Politics (I.1, 1252a17-20) to describe the technique of subdividing a composite object of study into the elements that make it up, in order to study the possible combinations. What theory is the basis for this method? Is it really a usual method for Aristotle? Enrico Rini responds to these questions, starting with the analysis of some passages of the Aristotelian corpus that refer to concepts of the (...) part and the whole. From these passages, Rini attempts to extrapolate a theory that Aristotle states explicitly only on occasion. The mereology that emerges from this study is not a formal theory, unlike the logical mereology present today, and therefore takes into account different types of the whole and the part, with a scope that has applications for the field of biology. (shrink)

This article discusses the ontological status of the parts of substances in Aristotle’s theory of categories. Since in this theory the substantial parts, as well as the wholes, are primary subjects of predication, i.e. substances, a part may be to its whole as Socrates is to Callias so that the mereological composition of substances can be regarded as an accident . It is argued here that in Cat. 7 Aristotle is trying to rule out this possibility by redefining the boundaries (...) of the category of relatives itself. Starting from the framework of the Academic debate and then following closely the text of Cat. 7, the author provides a detailed reconstruction of Aristotle’s argument in order to establish the reason for which the parts of substances hold such an uncertain status. Furthermore, he shows that the Categories do not provide a definitive solution to the mereological problem, which has rather to be sought in the Metaphysics. The following results are attained: a moderately systematic component is revealed in Aristotle’s Categories and a mereological element is detected in the very core of his theory of substance. (shrink)