From substrate to purposeGerčar, Jaka (Avtor) theory of the bookpublishing theorybook definitionreadingThe definitional boundaries of the book have grown increasingly unstable in an era of hybrid formats, platform publishing, and shifting media practices. Technical, institutional, and pragmatic approaches each capture aspects of the book’s status, yet none provides a framework that highlights the book’s enduring cultural authority. This article advances a causal-ontological model grounded in Aristotle’s four causes (material, formal, efficient, and final). It is argued that the first three causes are often implicitly acknowledged in publishing studies, whereas the final cause, understood as the book’s purposive orientation, has remained largely overlooked in debates on the ontology of the book. It is argued that this dimension, though not metaphysically essentialist, illuminates the book’s epistemic affordances, cultural resilience, and symbolic persistence. By distinguishing between ancillary and ultimate ends, the causal model accounts for the book’s dual status as commodity and cultural instrument. In doing so, it clarifies persistent taxonomic challenges and demonstrates how philosophical analysis can enrich the theory of publishing.20252026-06-18 16:12:10Neznano183778sl