Existential-Synthetic Ontology: Reframing Truth, Ethics, and Being in the Age of Generative AI

Generative AI has shifted algorithms from a backstage infrastructure to visible co-authors of culture. This paper proposes Existential–Synthetic Ontology (ESO), which models reality as a recursive triad of (i) the pre-conscious material–infrastructural ground (energy, compute, protocols, law), (ii) conscious interpretation and practice, and (iii) synthetic algorithmic artefacts/agents that act back upon the world. Truth is ontological efficacy, by this we mean that a phenomenon is ‘true-in-being’ to the extent that it makes consequential differences within this triad, gaining form, causal traction, and durable embeddedness.Drawing on critical realism, phenomenology, and posthumanism media theory, the paper formalises ESO and tests it against two emblematic cases (the viral ‘Pope in a puffer’ image and the licenced AI continuation of James Earl Jones’s voice). We operationalise entry into reality via three criteria; instantiation, causal traction, and relational embeddedness. The paper concludes by outlining ontological stewardship as an ethics for design and governance across educational, cultural, and technical domains. Reframing truth as efficacy clarifies what matters in a synthetic era: not only whether statements correspond but also whether artefacts and practices reshape the world.