This book confronts the fragmentation of meaning and the exhaustion of reason in the aftermath of postmodernity. Instinct, Reason and the Self in the Aftermath of Postmodernity: Beyond Reason argues that meaningful orientation cannot be restored through propositional reasoning alone. What must be recovered is instinct: embodied attunement to the world prior to deliberative thought. Following the collapse of grand narratives, we navigate a liquid terrain with conceptual tools designed for solid ground, one increasingly shaped by digital infrastructures and AI-driven systems of engineered salience, which together form the Sensorial Nexus: a state in which algorithmic mediation pre-organises perception, narrowing the space for reflective judgement and originality. Drawing on Arnold van Gennep's tripartite ritual schema, the book proposes the reawakening of instinct and introduces the DIEM Method, a practical framework for disengaging from the Sensorial Nexus and restoring interior coherence.