 What the proponent of EMT submits is that mental states themselves can partly supervene on extracranial artifacts (e.g., notebooks, iPhones) provided these extracranial artifacts play kinds of functional roles normally played by on-board, biological cognitive processes. For example, to borrow an (adapted) case from Clark and Chalmers (1998), suppose an Alzheimer’s patient, ‘Otto’, begins to outsource the task of memory storage and retrieval to his iPhone, having appreciated that his biological memory is failing. Accordingly, when Otto acquires new information, he automatically records it in his phone’s ‘memory app’, and when he needs old information, he (also, automatically and seamlessly) opens his memory app and looks it up. The iPhone comes to play for Otto the functionally isomorphic role that biological memory used to play for him vis-à-vis the process of memory storage and retrieval. Just as we attribute to normally functioning agents knowledge in virtue of their (non-occurrent) dispositional beliefs stored in biological memory (for example, five minutes ago, you knew that Paris is the capital of France), so, with EMT in play, we should be prepared to attribute knowledge to Otto in virtue of the ‘extended’ (dispositional) beliefs which are stored in his notebook, provided Otto is as epistemically diligent in encoding and retrieving information as he was before (e.g., Pritchard 2010b).