Late antique Gnosticism and Heidegger’s Existentialism are usually counted among the main theoretical targets of Hans Jonas’s philosophy of life and responsibility, since they are supposed to share the dualistic and nihilistic attitude the philosopher deemed most mistaken and pernicious. In particular, Gnosticism is commonly understood as the exact opposite of what Jonas strove to accomplish in his work. However, I think it is simplistic to relegate Gnosticism to a merely antagonistic role in the development of Jonas’s philosophy. My claim (...) is that Gnosticism, being a non-nihilistic form of dualism, might have been a relevant source of inspiration – although not the only one – for amending the flaws of Heidegger’s Existentialism. By taking a closer look at the essay Gnosticism, Existentialism, and Nihilism, this article aims to clarify the critical and constructive role that Gnosticism might have played in shaping some of the major traits of Jonas’s thought. The first part of this essay deals with Jonas’s ‘gnostic reading’ of Heidegger’s Existentialism and highlights the positive insights drawn from such interpretative strategy. The second part focuses on three main motives in Jonas’s philosophy that may be traced back to the gnostic narrative: value objectivity and vulnerability, human responsibility and involvement in the history of being, and the sense of belonging to a wider dimension capable of providing orientation and meaning to human life. (shrink)