I propose a discussion on the text "Aristotle's emendation of ontology". The study has been written by Professor Zdrakvo Peric and me. The text has been published in the Analele Universitatii din Craiova, Seria Filosofie, 52 (2/2023), pp. 35-69. I have uploaded my Word version of the study. On request, I shall send the printed version of the text. In our inquiry, we investigate elements of the foundations of Aristotle’s ontology. We concentrate our attention on aspects of the substance and the universal: we analyse the features which belong to substance qua substance and to universal qua universal, on the one hand, and the features which cannot belong to substance and universal, on the other hand. The mutual incompatibility between substance and universal and between the features which are respectively connected to substance and to universal are the central interest of our investigation. We furthermore inquire into the consequences of a wrong interpretation of the universal. The texts of Aristotle on which we base our study are Metaphysics Zeta 13, Zeta 14, and Zeta 16.