Current theories of context see context as composed of information that is localizable to individual utterances. Current theories of discourse grant that discourses have important global properties that are not so localizable. In this paper, I argue that context, even narrowly construed as whatever combines with a sentence to determine truth conditions, must have a discourse–global component. I identify a context–dependence phenomenon related to the linguistic concepts of topic and focus, isolate the pertinent feature of context, and show that this feature must be discourse–global in nature. I thus argue that context is as complicated as an entire discourse.