Abstract: This paper argues that Mullā Sadrā (1571–1640), a central figure in the Islamic world, provides a framework for reinterpreting René Descartes' (1596–1650) moral philosophy, particularly his conception of happiness. While Descartes is often studied within European intellectual history, his moral thought is deeply intertwined with broader metaphysical traditions spanning Islamic and European contexts. Both Mullā Sadrā and Descartes conceptualize happiness as the fulfillment of the soul through intellectual and metaphysical transformation, a shared framework rooted in their engagement with Avicennan and Neoplatonic legacies.

Existing scholarship on Descartes' moral philosophy has largely focused on his relationship to Stoicism, Augustinianism, and the Scholastic tradition (e.g., Stephen Menn's Descartes and Augustine; John Cottingham's Descartes' Philosophy of Mind). However, this emphasis has often neglected the transregional intellectual currents that shaped his thought, particularly the influence of Islamic philosophy mediated through Scholasticism (e.g., Richard C. Taylor's work on Avicenna's reception in Latin Europe; Dag Nikolaus Hasse's Avicenna's De Anima in the Latin West). Similarly, studies of Mullā Sadrā have primarily situated him within the Islamic philosophical tradition (e.g., Sajjad Rizvi's Mullā Sadrā and Metaphysics; Ibrahim Kalin's Knowledge in Later Islamic Philosophy), with little attention to his relevance for understanding early modern European thought.

This paper bridges these divides by placing Descartes in dialogue with Mullā Sadrā, demonstrating how both thinkers draw on Avicennan and Neoplatonic ideas to articulate a vision of happiness as the soul's ascent toward intellectual and moral perfection. Although Descartes and Mullā Sadrā differ in their epistemological commitments—particularly regarding the nature of knowledge and divine reality—their respective ethical frameworks converge in viewing happiness as the culmination of a teleological process. For both, the soul moves toward its highest possible fulfillment through a combination of intellectual realization and moral refinement. However, Mullā Sadrā's perspective challenges Cartesian assumptions about the nature of self-perfection, presenting an alternative model where happiness depends on the very structure of being itself. Rather than grounding human fulfillment in the cognitive mastery of reason and will, Mullā Sadrā measures the soul's perfection by its degree of existential intensity, as articulated in his doctrine of substantial motion (al-haraka al-jawhariyyeh).

By integrating Mullā Sadrā into the study of Descartes, this paper challenges the Eurocentric framing of early modern philosophy as a uniquely European phenomenon. It argues that recognizing the transregional conversations that shaped Descartes' thought not only expands the scope of early modern studies but also reveals deeper continuities in the philosophical search for human fulfillment across cultures. This approach contributes to a growing body of scholarship that seeks to decenter Eurocentric narratives in the history of philosophy, offering a richer understanding of Descartes' moral philosophy and highlighting the enduring relevance of cross-cultural philosophical dialogue.