Remarks and Admonitions

Late in life, probably in the 1030s, Avicenna changed how he wrote. al-Ishārāt wa-l-tanbīhāt (Remarks and Admonitions, also translated as Pointers and Reminders) is the last of his summaries of philosophy, and its preface addresses a reader eager to verify the truth for himself: it offers principles and outlines, which a sharp mind will find easy to work out in full. The device came from the late Greek commentators on Aristotle, who explained his obscure style as a way of training students to complete the arguments themselves. The book has two parts, logic in the first and physics and metaphysics in the second; only the logic is given here. It runs in ten short stages, each called a nahj (method), from the purpose of logic through single terms and definition, propositions and their modalities, contradiction and conversion, to the syllogism, demonstration and the fallacies. The ten categories, a fixture of the Aristotelian logic curriculum, get no section. Avicenna's logic so dominated what followed that historians divide Arabic logic into a period before him and a period after, and it was this compact arrangement, not the long logic of al-Shifāʾ (The Healing), that set the pattern for the later tradition. The logic ends with a warning: whoever has learned these rules and checked his reasoning as a reckoner checks a sum, and still goes wrong, is fit to give philosophy up. Readers have rarely taken the book up without a commentary beside it. Fakhr al-Dīn al-Rāzī, the theologian, wrote one that pressed hard against its arguments, and in the thirteenth century Naṣīr al-Dīn al-Ṭūsī, the astronomer and philosopher, wrote another to defend Avicenna against him.