 Second, the question one finds oneself asking amounts to, ‘What have I been doing?,’ and those characterizations of what one is doing that drive further choice will be largely framed using thick ethical concepts.  That is, rather than applying concepts like ‘good’ or ‘right’ to evaluatively neutral descriptions of one’s circumstances or activity, they will deploy descriptions whose very application depends on mobilizing one’s evaluative capacities.  (E.g., in the elaborate case study which led Bernard Williams to identify this class of concepts, there isn’t any way to mark out what counts as obscene, if one occupies only the evaluatively neutral view of a Martian exobiologist; Williams 1981b, and for background, see the entry on thick ethical concepts.) Williams controversially claimed that thick ethical concepts could not be factored into strictly factual and strictly evaluative components (for an overview, see Millgram 1995).  Brewer argues that the unity over time of dialectical activities supports Williams’s view on this point, and in addition, that our need to rely on thick ethical concepts undercuts the distinction we have used in framing this very survey, between theoretical and practical reasons – that is, respectively, reasons that figure into argument as to how the facts stand, and those that figure into arguments for doing one thing or another.