 Having introduced one important contextualist thesis, let’s return to the general question which faces the semantic theorist, which is: How do we tell when an expression is context-sensitive? Contextualism about knowledge, after all, can hardly get off the ground unless “knows” really is a context-sensitive expression. “I” and “here” wear their context-sensitivity on their sleeves; but “knows” does not. What sort of argument would suffice to show that an expression is an indexical?