Development of the Concept of Malignity in the History of Philosophical Ethics in the Islamic World (with an Emphasis on Khwajah Nasir al-Din Tusi's Philosophy)

Aristotle’s principle of middle term is commonly defined as avoiding excess and defect, which seems to be a quantitative concept at first sight. This interpretation has received some criticisms from the authorities in the field of ethics. Muslim thinkers have also taken some steps to criticize, examine, and possibly improve this principle. Their most important attempt in this regard has been the introduction of the concept of malignity to philosophical ethics in the world of Islam. This concept pays attention to both quality in addition to quantity and remedies some of the defects of Aristotle’s principle of middle term. It is noteworthy that an accurate review of Aristotle’s texts also indicates the presence of the element of malignity in his ethical system. This concept was firstly introduced by Khwajah Nasir al-Din Tusi in some parts of Akhlaq-i nasiri, and later Qadi Izzuddin Iji placed it in a more logical section among ethical discussions. Following them, many Muslim experts in the field of ethics accepted their idea of this concept and discussed it in their works. The present paper aims to explore the historical development of the concept of malignity and examine its significance in the related fields.