Translated by Pete Ferreira
Brentano takes on Aristotle's doctrine of the plurivocity of the being from the four fundamental meanings of the latter: (1) the first meaning is that of being for itself (ον καθ᾽ αυτω) and being by accident (ον κατά συμβεβηκός), this treatise – with particular attention to being by accident – occupies the second chapter. (2) the second meaning is that of being as true (ὂν ὡς ἀληθές), examined in chapter three. (3) The third meaning is that of being as potential or being in the act (ὄν δυνάμει και ἐνέργειᾳ), the theme of the fourth chapter. (4) Finally, the fourth and final fundamental meaning is that according to the figures of the categories (ὂν κατὰ τὰ σχήματα τῶν κατηγοριῶν), analyzed in chapter five. For Brentano, who – as has been said – interprets Aristotelian ontology as a doctrine of substance (the first category), this last fundamental meaning of being is the most important of the four.
The key part of Brentano's dissertation is precisely that in which he examines the different meanings of being according to the figures of the categories. There he faces the problems of the analogical homonymy of being identical found between pure synonymy and homonymy ἀπό τύχες, proposing a solution that is distinguished by two questions. Above all, for Brentano, sticking with the scholastic doctrine of analogy of proportionality and of analogy with respect to its own ends, he interprets the analogical unity of being in Aristotle as important; secondly, Brentano, having interpreted the unity of analogy as important, considers it possible to deduce or "divide" the categories as a systematic criteria for their classification. So, they are not at all like that rhapsodic approach that Kant and then Hegel criticize, but arise from an honest and proper systematic διαίρεσις of being.
As regards the first of the two aspects, Brentano critically discusses three interpretations of the Aristotelian doctrine of the categories (chap. V, § 1). A first interpretation, supported with some variations by Ch. A. Brandis, by L. Strümpell and by E. Zeller, sees in the categories not concepts true and proper, but only the predicate structure within which all real concepts must be ordered. A second and a third interpretation, indicating that the categories are not forms of predication by concepts, claim that they are rather universal concepts. These last two interpretations are distinguished in highlighting different aspects. The second interpretation considers the categories as concepts not in the sense of conceptual representations, of concepts taken separately, but in the logical sense of concepts of judgment, i.e. as parts of this latter and, therefore, as predicates, indeed, as universal predicates. A. Trendelenburg, F. Biese and T. Waitz would be the biggest supporters in the nineteenth century, but along with their interpretation coinciding with Brentano's, they were also translators that rendered κατηγορίαι with praedicamenta (and according to Trendelenburg, like ancient commentators such as Alexander of Aphrodisias, Aegean Alexander and Porfirio). The third interpretation, supported by H. Bonitz and C. Ritter, but accepted also by Hegel, agrees with the second in believing, against the first, that the categories are not the property of the concepts, but the concepts themselves. But, unlike the latter, it does not accept concepts as referring to judgment, but as universals, as chief of the senses of being and not so much as predication. It therefore intends to deny that the categories are mere predicates and that their scheme is made from a consideration that is exclusively logico-grammatical.