Thabit ibn Qurra (826-901) was one of history´s most original thinkers and displayed expertise in the most difficult disciplines of this time: geometry, number theory, and astronomy as well as ontology, physics, and metaphysics. Approximately a dozen of this shorter mathematical and philosophical writings are collected in this volume. Critically edited with accompanying commentary, these writings show how Thabit Ibn Qurra developed and reconceived the intellectual inheritance of ancient Greece in all areas of knowledge.