The relationship between language, thought, and reality was a topic of intense discussion among eighteenth-century philosophers, the source of which was Locke’s Essay Concerning Human Understanding. The author argues that Locke’s empiricism created a tradition of study due more to the philosopher’s inaccuracies/contradictions than to his correct insights. For Locke, humans are born without innate ideas and their knowledge is determined by experience derived from perception. He wanted to cancel scholastic language and the belief in faculties of mind capable of directly apprehending reality: instead, the mind is a clean slate which gets imprinted with simple sensory data, becoming more complex through further experience. Initial (nuanced) reactions to his theories came from Leibniz and Berkeley. But language remained theoretically external to understanding/reason until Condillac. For him language was fundamental in the evolution of reason and research had to begin with the historical origins of language in society. Condillac’s work was extended through critiques (Rousseau, Monboddo, Maupertuis, Girard, Diderot). Some also argued that language emerged through dialogue and that meanings were developed differently by communities (relativism). Finally, conservative reactions against empiricism (Harris, Reid, Herder) reaffirmed the belief that language could not be explained without some inherent human faculty.