Paul Florensky

This article presents a partial translation of the third "letter" of Pavel Florensky's major work, *The Pillar and Ground of the Truth* (1914), carried out by Constantin Andronikof. The approach is both philosophical and theological: Florensky examines the Trinitarian dogma as a response to the impasse of rational scepticism. The central idea is that the conciliar formula *homoousios*, as defended by Athanasius of Alexandria, expresses a supralogical truth irreducible to any rationalization: consubstantial unity and hypostatic distinction do not exclude each other, but mutually posit one another in a *coincidentia oppositorum*. The theological contribution is twofold: on the one hand, a rereading of the history of Trinitarian controversies showing that any deviation from the *homoousios* leads to Sabellianism or tritheism; on the other hand, a phenomenology of faith as a free and ascetic act enabling reason to transcend its own limits.