Avicenna is the most influential figure in the intellectual history of the Islamic world. This book is the first comprehensive study of his theory of science, which profoundly shaped his philosophical method and indirectly influenced philosophers and theologians not only in the Islamic world but also throughout Christian Europe and the medieval Jewish tradition. A sophisticated interpreter of Aristotle’s Posterior Analytics, Avicenna took on the ambitious task of reorganizing Aristotelian philosophy of science into an applicable model of scientific reasoning, striving to identify conditions of certainty for scientific assertions and conditions of adequacy for real definitions. Riccardo Strobino combines philosophical and textual analysis to explore the scope and nature of Avicenna’s contributions to the logic of scientific reasoning in his effort to recalibrate Aristotle’s model and overcome some of its internal limitations. Focusing on a broad array of philosophical innovations at the intersection of logic, metaphysics, and epistemology, this book casts light on an essential aspect of the thought of the preeminent philosopher and physician of the Islamic world.