A common assumption in psychology and linguistics is that words map onto pre-existing meanings. I will argue that this view is mistaken and that words play a much more central role in creating meaning than is generally acknowledged. In the first part of the talk, I will present a range of empirical evidence for the functions of language beyond communication, focusing on categorization and visual perception. On the presented view, many of the unique aspects of human cognition stem from the power of words to flexibly create categories from perceptual representations, allowing language to act as a high-level control system for the mind. In the second part, I will discuss the consequences of adopting this view for thinking about the evolution of language and culture.