Abstract: The debate concerning the phenomenology of thought is marked by severe disagreement about how best to characterize a given conscious thought on the basis of introspective reflecting upon it. In this paper I focus on the fact of this introspection-based disagreement – in particular, on its epistemic import for participants in the debate. How ought these philosophers respond when facing such radical disagreement about the deliverance of introspection? I argue that the fact of such disagreement itself should lead participants to be less confident – or even to suspend judgement – in their own introspection-based claims. If that is right, then to the extent that the debate about the phenomenology of thought is carried out by appeal to introspective evidence, this constitutes a serious epistemological concern. At the very least, if this is the epistemically appropriate response, non?trivial reliance of introspective evidence in the debate comes under pressure.