This work of Galen represents one of the mile stones and reference works of pre-modern pharmacology. Ḥunayn ibn Isḥāq produced a complete and highly refined Arabic translation, as coronation of a long lasting interest in this work. The Arabic text, however, is not merely a collateral transmission of the Greek original. This seminar will show the students the independent development of the Arabic tradition, the peculiarities of the manuscript witnesses, and the editorial approach to this rich text. This historical and textual analysis aim at showing to its full extent how the richness and complexity of the Arabic version of Galen’s On Simple Drugs is the best contribution that can be offered for a deeper understanding of the Greek Galen.