  One other distinction that is worth making in this connection is the distinction between a preemptive duty to obey and a duty that is not preemptive. A preemptive duty is one that replaces other duties. It puts other duties out of play when it comes into play. A preemptive duty is not weighed against other duties that might relate to what one is thinking of doing. Of course, a preemptive duty may not preempt all other considerations, its preemption may operate only with a limited scope and thus preempt only some limited set of considerations.