 A simple example illustrates this logic. Consider a prohibition on emitting more than 75 parts per billion of sulfur dioxide per hour into the air. This prohibition gives a power-generating plant reason not to emit more than that amount of sulfur dioxide per hour. But it also excludes a variety of other first-order reasons for action from the plant’s consideration. On Raz’s account, the firm should not act on, for instance, the fact that emitting more than 75 parts per billion of sulfur dioxide per hour would increase its profits (or lower its costs). The obligation would not, presumably, exclude reasons that arose from a situation in which a temporary failure to exceed the emissions standard posed a substantial threat to the health and safety of employees. 