In his doctoral dissertation Von der mannigfachen Bedeutung des Seienden nach Aristoteles Brentano tried to show that (against criticism of this) one could indeed give a principle defense of Aristotle's table of categories as a coherent system. In later texts Brentano appears sharply critical of Aristotle, mainly in respect to Aristotle's mereology, or theory of part and whole, and to his theory of substance and accident. It is argued that Brentano hadn't observed that Aristotle's belief that there are as many (...) predicative senses of 'be' as there are categories of being is based not on his mereology but on his theory of definition. Overlooking this Brentano was led to far reaching inadequate ontological consequences. (shrink)