I will introduce six constraints that should guide the formulation and use of DE. One goal in listing them is to engage in dialectical fair play by ruling out criticisms of the doctrine that are directed at misformulations of DE or that result from misapplications of it. Each of these constraints should be acceptable to any proponent of DE. Yet when these constraints on the application of DE are respected, it becomes clear that many of the examples provided as illustrations (...) of DE actually illustrate other, more interesting uses of the contrast between intention and foresight. (shrink)