The debate between internalists and externalists about mental content has proven exceptionally intractable; there is little agreement even on the implications of each of these positions. The culprit, I think, is an ambiguity in the terms “externalism” and “internalism”, which they inherit from an ambiguity in the notion of “intrinsic to the thinker” that defines these positions. I argue that this ambiguity is ineliminable. Any way of explicating “intrinsic to the thinker” will clash with the usual taxonomy of leading externalist and internalist views, or construe these positions as involving commitments that are standardly regarded as orthogonal to them—and, in some cases, explicitly rejected by their most prominent exponents. The moral is stark. The sense that there is a substantive, defining commitment of externalism or internalism—even one that is vague or underspecified—is illusory. There is no univocal thesis of externalism or internalism.