Human language is regarded by many as a premier example of a natural biological system. Its structural complexity, the rapidity and ease with which it is learned by young children, the importance of sensitive periods in acquisition over the lifetime, and its neural specificity all suggest that the system is highly specialized--finely tuned to fulfill a clear adaptive function. Understanding the nature of this biological system, its growth over development, its evolution, and its neural basis form some of the deepest questions that are currently addressed within cognitive science. This symposium brings together key figures in the study of language as a biological system to discuss recent advances in our understanding from the perspectives of linguistics, cognitive neuroscience, and philosophy. This symposium is the first in the new series, The Governing Board Symposium, sponsored by the Governing Board of the Cognitive Science Society, and intended to address the most significant topics of our time by drawing on the many disciplines that are at the heart of cognitive science.