 Avicenna had an excellent education on all subjects, but he dwells at length in the Autobiography on his study of the intellectual sciences, that is, the philosophical curriculum in practice in the Hellenic schools of higher education in late antiquity, notably in Alexandria. These consisted of logic as the instrument of philosophy (the Organon), the theoretical sciences—physics (the natural sciences), mathematics (the quadrivium: arithmetic, geometry, astronomy, and music), and metaphysics—, and the practical sciences—ethics, oeconomics (household management), and politics. Avicenna makes a point to say that he studied these subjects all by himself, in this order, at increasing levels of difficulty, and that he achieved proficiency by the time he was eighteen. At about that time he was allowed to visit the library of the Samanid ruler, just mentioned above, where, he says, he “read those books, mastered their teachings, and realized how far each man had advanced in his science” (Gohlman 1974, 36; transl. Gutas 2014a, 18). Shortly thereafter he wrote his first work, Compendium on the Soul (GP 10), dedicated to the ruler in apparent gratitude for the permission to visit the library. His fame grew, and when he was twenty-one he was asked by a neighbor named ʿArūḍī to write a “comprehensive work” on all philosophy, which he did (Philosophy for ʿArūḍī, GS 2), treating all subjects listed above except mathematics; another neighbor, Baraqī, asked for commentaries on the books of philosophy on all these subjects—essentially the works of Aristotle—and he obliged with a twenty-volume work he called The Available and the Valid (i.e., of Philosophy, GS 10) and a two-volume work on the practical sciences, Piety and Sin (GPP 1). His father having died in the meantime, he was forced to take up, but clearly had no difficulty in finding, a post in the financial administration of the Samanids. 