The central proposition of this essay is that knowledge is not primarily a collection of disciplines, texts, or representations, but an infrastructure: a structured, operational environment in which concepts are organised, executed, validated, stabilised, distributed, mediated, expanded, circulated, and preserved. What we call disciplines—linguistics, art, science, architecture, media, urbanism—can be reinterpreted not as separate domains of knowledge but as operational layers within a single epistemic system. From this perspective, knowledge behaves less like a library and more like a city: it has structure, regulations, buildings, territories, communication systems, growth patterns, movements, and infrastructures that ensure its persistence over time. The problem of knowledge, therefore, is not only a problem of truth, but a problem of organisation, maintenance, and survival. If knowledge is treated as infrastructure, then a Knowledge Organization System is not merely a taxonomy or classification scheme, but a multi-layered operational structure. At the structural level, language organises and stabilises meaning through repetition and positional relations within a corpus. At the operational level, protocols—procedures, methods, instructions—transform structure into executable actions. At the epistemic level, validation processes determine which propositions stabilise and persist. At the systemic level, feedback and recursive operations regulate the reproduction of the system over time. At the structural-material level, architecture provides support, giving durable form to knowledge through institutions, publications, and platforms. At the territorial level, urbanism distributes knowledge across spaces, centres, and networks. At the mediatic level, media technologies record, transmit, and visualise knowledge. At the biological level, morphogenesis explains growth, branching, and transformation. At the dynamic level, movement describes circulation, exchange, and interaction. Finally, at the infrastructural level, integration ensures long-term persistence through archives, repositories, standards, and governance systems. This model can be described as an Epistemic Infrastructure Model because it shifts the focus of epistemology from justification alone to organisation, regulation, and persistence. Classical epistemology asked: How do we know? An infrastructural epistemology asks: How does knowledge persist? How is it organised? How does it circulate? What structures allow it to survive over time? In this sense, truth is only one component of knowledge; persistence, reproducibility, and integration are equally important. A theory that is true but not stored, transmitted, or reproduced disappears. Infrastructure, therefore, becomes a condition of knowledge. Such a model also functions as a Transdisciplinary Ontological Framework because it does not place disciplines side by side but reorganises them according to their function within a system. Linguistics becomes structure, conceptual art becomes protocol, epistemology becomes validation, systems theory becomes regulation, architecture becomes support, urbanism becomes territory, media becomes mediation, morphogenesis becomes growth, dynamics becomes movement, and infrastructure becomes integration. These are not metaphors but functional correspondences. Each field describes a necessary operation that any knowledge system must perform in order to exist and persist. From this perspective, a General Theory of Knowledge Systems would argue that any durable body of knowledge—science, law, religion, art, or technology—must solve the same ten problems: how to structure information, how to execute operations, how to validate propositions, how to regulate reproduction, how to support structures materially, how to distribute knowledge spatially, how to transmit it, how to grow, how to circulate, and how to preserve it. Different civilizations and institutions solve these problems differently, but the operational fields remain constant. What changes is the form of the infrastructure, not the necessity of the functions. This leads to what can be called an Infrastructure Theory of Knowledge: knowledge persists not because it is true alone, but because it is infrastructurally supported. Libraries, universities, archives, journals, servers, standards, classification systems, and digital repositories are not secondary to knowledge; they are part of knowledge itself. Knowledge is therefore inseparable from its storage systems, transmission media, institutional supports, and technical standards. Epistemology becomes inseparable from logistics. An Operational Epistemology follows from this: knowledge must be understood as something that operates. Concepts do not simply mean; they do things. They organise fields, structure institutions, produce technologies, and transform territories. A concept that does not operate disappears; a concept that operates becomes infrastructure. Therefore, the history of knowledge can be understood as the history of concepts that became operational and infrastructural. Finally, this model can be described as a Structural Model of Transdisciplinary Systems because it provides a common framework in which different disciplines can be understood according to what they do within a system rather than what they study as objects. This shift—from objects to operations—allows disciplines to be integrated into a single framework without collapsing their differences. Each field retains its methods and history, but its systemic function becomes legible within a larger structure. To think knowledge as infrastructure is to move from a philosophy of knowledge to an architecture of knowledge. The question is no longer only whether knowledge is true, but whether it is structured, executable, validated, regulated, supported, distributed, mediated, expanded, circulated, and preserved. Knowledge, in this sense, is not only something we think; it is something we build, maintain, and inhabit.