RHETORIC IS VERY LIKE an umbrella. Under its expansive shade, more or less comfortably, cluster a variety of subjects -semantics, logic, usage, style. Rhetoric is very like an arch. It spans widely, bridging psychology, linguistics, sociology, philosophy. Rhetoric is very like a dynamo. It is the machinery for generating the ideas and language of communication. Rhetoric is sometimes very like a whale, with its mouth open, sweeping the ocean. Rhetoric is also very like a jelly fish.