  Although Heidegger does not put things this way, the complex intermediate realm of the un-ready-to-hand is seemingly best thought of as a spectrum of cases characterized by different modes and degrees of engagement/disengagement. Much of the time Dasein's practical problem solving will involve recovery strategies (e.g., switching to a different mode of transport) which preserve the marks of fluid and flexible know-how that are present in ready-to-hand contexts. In the limit, however (e.g., when a mechanic uses his theoretical knowledge of how cars work to guide a repair), Dasein's problem solving activity will begin to approximate the theoretical reasoning distinctive of scientific inquiry into present-at-hand entities. But even here Dasein is not ‘just theorizing’ or ‘just looking’, so it is not yet, in Heidegger's terms, a pure disengaged subject. With this spectrum of cases in view, it is possible to glimpse a potential worry for Heidegger's account. Cappuccio and Wheeler (2010; see also Wheeler 2005, 143) argue that the situation of wholly transparent readiness-to-hand is something of an ideal state. Skilled activity is never (or very rarely) perfectly smooth. Moreover, minimal subjective activity (such as a nonconceptual awareness of certain spatially situated movements by my body) produces a background noise that never really disappears. Thus a distinction between Dasein and its environment is, to some extent, preserved, and this distinction arguably manifests the kind of minimal subject-object dichotomy that is characteristic of those cases of un-readiness-to-hand that lie closest to readiness-to-hand.