This essay undertakes a comparative philosophical investigation of two foundational epistemological doctrines: William James's notion of "pure experience," as elaborated in his radical empiricism, and Muhammad Husayn Tabātabā'ī's concept of ʿilm hudūrī (knowledge by presence), as developed within the tradition of Islamic philosophical psychology and epistemology rooted in the Transcendent Wisdom (al-ḥikma al-mutaʿāliyya) of Mullā Ṣadrā. Despite emerging from radically different intellectual traditions—American pragmatism and the Shīʿī philosophical tradition—both thinkers converge on a shared philosophical intuition: that the foundational stratum of knowing is a pre-representational, immediate form of acquaintance with reality that precedes and grounds all conceptual, propositional, and representational structures of cognition. By situating each thinker within his respective philosophical lineage, analyzing the internal structure of each doctrine, and tracing the points of convergence and divergence between them, this essay argues that pure experience and ʿilm hudūrī represent parallel, independently developed responses to the epistemological impasse generated by classical representationalism. Their convergences—including the shared critique of atomism, the epistemological priority of acquaintance over propositional knowledge, and the paradigmatic status of self-knowledge—reveal a structural homology across traditions, while their divergences—concerning the metaphysical status of the self, the relationship between knowing and being, the scope of mystical knowledge, and the question of infallibility—reflect genuinely different and philosophically illuminating philosophical commitments. The comparison demonstrates that cross-traditional dialogue between Islamic and Western epistemology is not merely a cultural exercise but a philosophically productive enterprise capable of illuminating perennial questions about consciousness, self-knowledge, and the pre-representational ground of cognitive life.