The doctrine of the unity of the intellect and the intelligible is among the most significant issues in Islamic philosophy and occupies a central place in Transcendent Philosophy (al Ḥikmah al Mutaʿāliyah). Ṣadr al Mutaʾallihīn (Mullā Ṣadrā) advanced two principal arguments in support of this doctrine, commonly known as the Argument from Correlativity (burhān al taḍāyuf) and the Argument from Light and Darkness (burhān al nūr wa l ẓulmah). Owing to their complexity, these arguments have been the subject of numerous critiques by later thinkers. Among the most prominent critics is Ayatollah Muḥammad Taqī Miṣbāḥ Yazdī, who raised a series of objections against both arguments.
In a previous article entitled “A Critical Study of Miṣbāḥ’s Objections to Ṣadrā’s Proofs for the Unity of the Knower and the Known,” the present author responded to these objections in defense of the Ṣadrian position. Subsequently, Dr. ʿAlī Arshad Rīyāḥī, in his article “In Defense of Miṣbāḥ’s Objections to Ṣadrā’s Proofs for the Unity of the Intellect and the Intelligible,” sought to vindicate Miṣbāḥ’s criticisms and to challenge the adequacy of those responses. The present paper critically examines Rīyāḥī’s claims. To this end, it first revisits Ṣadrā’s original arguments and Miṣbāḥ’s objections, and then systematically evaluates the author’s earlier replies alongside the counter critiques advanced by Rīyāḥī. The analysis shows that many of Rīyāḥī’s defenses rely on imprecise interpretations of Ṣadrā’s philosophical framework. In particular, Ṣadrā’s conception of cognitive forms as modes of existence whose very reality consists in being known stands in sharp contrast to the accidentalist conception of knowledge presupposed in Rīyāḥī’s defense. Accordingly, this study concludes that the Ṣadrian proofs for the unity of the intellect and the intelligible within Transcendent Philosophy remain philosophically defensible.