In these lectures, I would like to focus attention on the question, What contribution can the study of language make to our understanding of human nature? In one or another manifestation, this question threads its way through modern Western thought. In an age that was less self-conscious and less compartmentalized than ours, the nature of language, the respects in which language mirrors human mental processes or shapes the flow and character of thought – these were topics for study and speculation by scholars and gifted amateurs with a wide variety of interests, points of view, and intellectual backgrounds. And in the nineteenth and twentieth centuries, as linguistics, philosophy, and psychology have uneasily tried to go their separate ways, the classical problems of language and mind have inevitably reappeared and have served to link these diverging fields and to give direction and significance to their efforts. There have been signs in the past decade that the rather artificial separation of disciplines may be coming to an end. It is no longer a point of honor for each to demonstrate its absolute independence of the others, and new interests have emerged that permit the classical problems to be formulated in novel and occasionally suggestive ways – for example, in terms of the new perspectives provided by cybernetics and the communication sciences, and against the background of developments in comparative and physiological psychology that challenge long-standing convictions and free the scientific imagination from certain shackles that had become so familiar a part of our intellectual environment as to be almost beyond awareness.