Avicenna’s ground-breaking view of logic as both a tool for other sciences and a science in its own right has already attracted scholars’ attention and has been studied in several different respects. The present paper aims to address a specific issue entailed by considering logic as a science in its own right: that is, assessing the relation in which logic as a science stands to the other sciences, and particularly to metaphysics and psychology. The inquiry will focus on a fundamental, (...) yet tricky, passage of chapter I.4 of Avicenna’s Kitāb al-Madḫal, the opening work of his most comprehensive philosophical summa, the Kitāb al-Šifāʾ (Book of Healing). Due to the obscurity of some of Avicenna’s references, chapter I.4 “on the subject-matter of logic” has stimulated numerous attempts at interpretation from the Middle Ages to today. In this paper, I will attempt to provide a new reading of the chapter in light of Avicenna’s definition of the epistemological status of science in Burhān II.7. (shrink)