Chapter 5: What Truly Exists

Koch leverages Integrated Information Theory to establish a rigorous framework distinguishing between intrinsic existence, which refers to what an entity experiences from its own perspective, and extrinsic existence, which describes how things appear to external observers. The theory proposes that true existence requires entities to possess causal power characterized by five essential properties: intrinsic nature, specificity, integration, determinateness, and structured organization. These axioms of experience map onto corresponding physical postulates that can be quantified through integrated information, denoted as Φ. A central argument presented is that consciousness constitutes a structure of cause-effect relationships rather than a function, algorithm, or computational process, fundamentally challenging conventional understandings of what makes something real. Koch explores the implications of this framework by revisiting classical philosophical problems such as the Great Divide of Being, suggesting that conscious entities occupy a unique and rare position in the universe while the overwhelming majority of physical phenomena remain non-conscious. The chapter establishes that most entities and systems typically considered real possess only derivative existence, existing primarily in relation to conscious observers rather than in themselves. This theoretical foundation redefines reality according to the capacity for subjective experience, proposing that sentience itself represents the most fundamental criterion for genuine being and that consciousness is not incidental to existence but rather constitutive of it.