 As indicated earlier, there are two slightly different questions theorists might have in mind when they ask: “Are we measuring the right thing?” On the one hand, one might be asking whether a particular instrument developed to help clinicians assess capacity is empirically valid. Or (closely related), one might be asking whether a particular empirically valid instrument developed in one context, is applicable in a different legal context. On the other hand, one might be asking a deeper question about whether the underlying standards which inspired the development of the instrument, and which the instrument supposedly tracks, are really themselves adequate. In short, the second question challenges the underlying framework itself, asking whether we ought to be considering things that it fails to capture. Here, the first sort of question will be considered briefly before turning to the second. 