Ascetic discipline (riyāḍa) has always been accompanied by the question of whether it can bring about an existential change in the soul or merely regulate its qualities. The answer depends on each philosophical system's conception of the soul's nature and the possibility of its intrinsic transformation. Ibn Sina, emphasizing the immateriality and stability of the soul's substance and denying substantial motion, restricts perfection to the realm of accidents. In contrast, Mulla Sadra, based on the principality of existence (aṣālat al-wujūd), the gradation of existence (tashkīk al-wujūd), and intensifying substantial motion (al-ḥaraka al-jawhariyya al-ishtidādiyya), considers the soul as a fluid, ever-becoming reality. The main question is: assuming the ontological principles of each system, by what mechanism can asceticism generate soul perfection, and is a coherent explanation of its existential effect possible within Ibn Sina's framework? In the Avicennan system, asceticism plays a regulative role for theoretical reason, whereas in transcendent theosophy it is identical to the path of the soul's substantial realization.

The present study adopts an analytical-critical approach and employs qualitative content analysis of primary philosophical texts (al-Shifāʾ, al-Najāt, al-Ishārāt, al-Asfār al-arbaʿa, Mafātīḥ al-ghayb, and Shawāhid al-rubūbiyya). Its innovation lies not in a mere comparison of the two views or an isolated analysis of the foundations of the soul, but in uncovering the practical consequences of ontological principles and demonstrating the deep opposition between asceticism as accidental purification and asceticism as substantial transformation. This approach provides a criterion for measuring the internal coherence of philosophical systems by examining the relation between theory and practice. The structure of the article is as follows: after a conceptual analysis of religious asceticism, the path of soul perfection and the place of asceticism in Ibn Sina's thought and its critique, then Mulla Sadra's view on the genesis and perfection of the soul and the existential role of asceticism, and finally a comparative discussion and conclusion.

Conclusion

The relationship between practical conduct and the theory of the soul in Islamic philosophy is not a marginal issue but a decisive test for the internal coherence of any intellectual system. The analysis of the Avicennan and Sadrian systems reveals that the kind of relation established between asceticism and the perfection of the soul directly depends on the antecedent ontological frameworks that each philosopher conceives for the human soul.

In Ibn Sina's philosophy, the soul is defined as an eternal, fixed intellectual substance. This conception relegates any movement and change to the margin of accidents and qualities. In such a structure, asceticism inevitably acquires a secondary, serviceable function: a tool for harmonising the cognitive faculties and creating mental readiness for the reception of intelligibles. The fundamental question that challenges this framework is: how can an act that occurs only at the level of accidents lead to a goal described as intrinsically existential and substantial – such as connection with the Active Intellect or ultimate happiness? The fixed soul is ultimately summoned to a perfection that, for its attainment, requires a transformation whose occurrence in the substance of the soul is rendered impossible by the theoretical principles. This is the internal structural contradiction that makes explaining practical mysticism within this system difficult.

In contrast, transcendent theosophy (al-ḥikma al-mutaʿāliya), by grounding the theory of the soul on intensifying substantial motion and the gradation of existence, dissolves this puzzle from the very beginning. On this view, the soul is a fluid process whose identity depends on its successive becomings. Religious asceticism within this framework is not a marginal act but the conscious, voluntary form of that very intrinsic movement. Purification (tazkiya) and adornment (taḥliya) are exactly the outward stages of the soul's existential becoming. Hence, there is no gap between what the soul is (a fluid substance), what it does (asceticism), and what it becomes (ultimate perfection). This existential continuity between theory and practice is the distinguishing strength of transcendent theosophy.

This study reveals the opposition of two anthropological models in the Islamic philosophical tradition: the static model of essences versus the dynamic model of existences. The choice between asceticism as psychological exercise and asceticism as existential birth depends on this fundamental choice. From this perspective, Mullā Ṣadrā's innovation should be seen as extending substantial motion from the natural world to the realm of man and spirituality – an act that elevates philosophy from a mere description of the soul to a participation in explaining the path of its realisation. Thus, answering the question of the relation between asceticism and the perfection of the soul ultimately becomes a criterion for measuring the explanatory power and internal coherence of an entire philosophical system.