There is no doubt that AI research has made significant progress, both in helping us understand how the human mind works and in constructing ever more sophisticated machines. But, for all this, its conceptual foundations remain remarkably unclear and even unsound. In this paper, I take a fresh look, first at the context in which agents must function and so how they must act, and second, at how it is possible for agents to communicate, store and recognise (sensory) messages. This analysis allows a principled distinction to be drawn between the symbolic and connectionist paradigms, showing them to be genuine design alternatives. Further consideration of the connectionist approach seems to offer a number of interesting clues as to how the huma...