The reception of Aristotle's logic in Late Antiquity is a largely understudied topic. Building on a previous monograph entirely dedicated to Alexander of Aphrodisias' logic (Georg Olms, 2011), I explore in these pages the aftermath of Aristotle's logical thinking from the 1st century BC to the 6th century AD. This book is designed to present the internal coherence of a decade-long exploration of this hitherto understudied page of the history of Western thought. I pay attention to the key role of Alexander of Aphrodisias thanks to whom a peculiar version of Aristotle's logic was handed over to the later tradition, and I stress that Alexander's systematization is only one among the possible readings of the Organon, as is shown by the radically different syllogistic theory outlined by Boethus of Sidon.