The brief but prolific treatise of “Istiqṣāʾal-Naẓar fi-l-Baḥth ʿan al-Qaḍāʾ wa-l-Qadar” is one of the monographs of the famous Imami theologian, Ḥasan ibn Yūsuf ibn Alī ibn Muṭahhar, known as Al-ʿallāma al-Ḥillī (648- 726), which concerns the controversial issue of man predestination and free will. In this work, he has tried to explain the views and arguments of the proponents of predestination or human free will in performing various acts, and then to explain the correct position on this issue based on rational and narrative reasons. In the present article, first of all, the most important writings of the theologians before Al-ʿallāma-al- Ḥillī on the subject of predestination and free will are introduced. then, the structure and content of the treatise “Istiqṣāʾal-Naẓar”, the date of its writing, the various published editions of the work, the commentaries written on it, as well as the valuable and old manuscript of the treatise are examined.