  This theory grew out of direct consideration of the problems in temporal reasoning described above in  Section 4.5,  and especially the Yale Shooting Scenario. In  Morgenstern &amp; Stein 1994, Morgenstern and Stein seek to find a general, intuitively motivated logical framework that solves the difficulties. They settle on the idea that unmotivated actions are to be minimized, where an action (“actions” construed generally enough to include any change) can be motivated directly, e.g. by an axiom, or indirectly, through chains of motivations. The key technical idea of the paper is a (rather complicated) definition of motivation in an interval-based temporal logic. In  Morgenstern 1996, Morgenstern presents a summary of the theory, along with reasons for rejecting its causal rivals. The most important of these reasons is that these theories, based on the Situation Calculus, do not appear to generalize to cases allowing for concurrency and ignorance. She also cites the failure of early causal theories to deal with retrodiction. 