 In contrast, self/other parity (Section 2.1) and self-detection (Section 2.2) accounts of introspection or self-knowledge appear to stand in tension with infallibilism. If introspection or self-knowledge involves a causal process from a mental state to an ontologically distinct self-ascription of that state, it appears that, however reliable such a process may generally be, there is inevitably room in principle for interference and error. Minimally, it seems, stroke, quantum accident, or clever neurosurgery could break otherwise generally reliable relationships between target mental states and the self-ascriptions of those states. Similar considerations apply to self-shaping (Section 2.3.2) and expressivist (Section 2.3.3) accounts, to the extent that these are interpreted causally rather than constitutively.