In Islam, the concept of the heart (qalb) is central to the mystical doctrine of soul and discipline. Sufis often connect this term to the concept of “fluctuation” (taqallub), which shares the same Arabic root, q-l-b, and claim that the heart is called thus because it fluctuates. Some modern scholars have contended that Ibn ʿArabī (d. 1240), known as the greatest mystic of Islam, also described the heart using this semantic connection with “fluctuation.” However, these scholars have not considered discussions made by the Sufis before him. It thus remains unclear which aspects of his theory are distinct from earlier thought. With the aim of resolving this problem, I clarify the originality of his discussion connecting “heart” to “fluctuation” through a comparison with his Sufi predecessors.

　Famous Sufis before Ibn ʿArabī, including Sahl al-Tustarī (d. 896), Abū Ḥāmid al-Ghazālī (d. 1111), and Rūzbihān Baqlī (d. 1209), regarded the “fluctuation” as the essential characteristic of a heart. Inheriting this concept, Ibn ʿArabī explained the “fluctuation of a heart” in the framework of his own theory of “new creation” (khalq jadīd), which reflects the constant fluctuation of the whole cosmos. In this theory, the semantic connection of “heart” and “fluctuation” offers a base to examine the relationship between the human heart and the fluctuating cosmos. This phenomenon is not found in earlier thought; thus, it is considered a fruit of his own thought.

　Ibn ʿArabī is said to have inherited previous mystical ideas and developed them into ontological mystical philosophy, or ʿirfān. The concept of the heart, which belongs to the doctrine of human soul, is closely tied to the ontological doctrine of creation in his system. This phenomenon appears to be one aspect of his historical role in constructing Islamic mystical philosophy.