Abstract
What triggers the execution of actions? What happens in that moment when an action is triggered? What mental state is there at the moment of action-execution that was not there a second before? My aim is to highlight the importance of a thus far largely ignored kind of mental state in the discussion of these old and much-debated questions: motor imagery. While there have been a fair amount of research in psychology and neuroscience on motor imagery in the last 30 years or so, it is only recently that we start to understand the important role motor imagery plays in action initiation. And if, as these findings suggest, motor imagery plays an important role in action initiation, we can make progress not only in understanding action initiation in general but also in understanding what goes wrong in akratic actions and in relapse actions. Finally, this new picture of action-initiation also has far-reaching consequences for the relation between motivation and causation in naturalistic action-explanations.