This book investigates the historical development and conceptual evolution of the distinction between the terms 'language' and 'dialect'. Raf Van Rooy, a scholar in classical linguistics and the history of ideas, utilizes a vast array of primary sources from antiquity to the modern era to trace how these categories were constructed. The work argues that the binary is not a natural linguistic reality but a product of socio-political and ideological frameworks that have shifted over centuries.

Experts recognize this work as a rigorous contribution to the history of linguistics that clarifies the arbitrary nature of language boundaries. Readers frequently note the academic density of the prose, which is intended for researchers and students of historical linguistics.