The Scale of Language confronts a defining challenge of the GenAI era: the accelerating volume of machine generated text, produced with statistical smoothness and at unprecedented speed, creates a structural risk of linguistic homogenization. The danger is not scarcity but semantic drift, conceptual opacity, the erosion of reasoning visibility, and a loss of expressive depth. Evaluating linguistic quality therefore becomes essential for preserving clarity, meaning, interpretive reliability, and ultimately the human sovereignty over language. This book develops a principled pathway for meeting that challenge by integrating cognitive adequacy with statistical coherence through a dual foundation architecture. It introduces PhilEntropy, grounded in cognitive linguistic entropy, to capture the depth, relevance, and interpretive structure of human meaning, and LogiEntropy to characterize the distributional and structural regularities that statistical systems produce. Their integration forms the Linguistic Entropy Quotient (LEQ), a three layer evaluative framework that unifies perception, interpretation, and expression into a coherent measure of linguistic quality, including an expression spectrum that differentiates levels of linguistic quality. Through this architecture, the book provides a foundation for understanding how language functions across scientific writing, education, governance, and other domains where conceptual rigor is essential. It is written for researchers, educators, scientific writers, AI practitioners, and interdisciplinary scholars seeking a rigorous and actionable framework for evaluating linguistic quality in contexts where human and generative systems increasingly operate within shared expressive environments.