People produce many ideas. However, only some of the ideas they produce are valid, not all. The logic field focuses on these valid thoughts and tries to determine the structures related to them. For this reason, it is essential in terms of their consistency and validity to put forward the ideas, and therefore the information, produced in their field for each discipline, whether it is within the positive sciences or human and social sciences, using these structures, in other words, in cooperation with the field of logic. Considering this point, logic has been seen for centuries as a preliminary discipline to be learned before learning other fields. Works have been written as a summary for this reason. Athir al-Din al-Abhari is one of the thinkers who worked in this field. His relatively short and lexical work, which he calls Isaghuji, has been seen as an introduction to logic in the Islamic world for centuries and has been taught in schools. In this study, Isaghuji of al-Abhari will be examined in terms of modern logic. In this direction, the propositions and arguments in this book will be expressed symbolically. Besides, the consistency and validity of these symbolized propositions and inferences will be checked. Thus, the truth tree, a control method used in modern logic, will be used.