This book introduces the philosophical system of Avicenna (980-1037), the most important and influential philosopher in the medieval Islamic world. Avicenna’s thought is here described by reference to a number of texts, most centrally his masterpiece of brief exposition, Pointers and Reminders (al-Isharat wa’l-tanbihat). After a short biography, and a general account of the practice of philosophy in Avicenna’s day, the book presents Avicenna’s logic, metaphysics and psychology, paying special attention to how points in his philosophy are formulated to find a place for the central doctrines of Islam. The final chapter in the book sketches the influence Avicenna exercised over subsequent philosophers, both in Islam and in the West. A section on further reading introduces the reader to more advanced studies on Avicenna’s life and thought, serving as a point of departure for readers who intend to go more deeply into the works of this fascinating thinker.