Abstract
It is one thing for a scientist to speak a language in which he can conduct and communicate his investigations, another for him to possess a reflective understanding enabling him to explain the nature and workings of that language. Many who have sought such an understanding have held that the concepts of “meaning,” “reference,” and “theoretical term” play a crucial role in developing it. But others — instrumentalist skeptics about reference, Quinean skeptics about meaning, and skeptics about the theory/observation distinction — have denied this.