 Since 2000, a new ‘dynamical’ approach to spacetime structure has emerged in the works of Robert DiSalle (2006) and especially Oliver Pooley and Harvey Brown (2001, 2006). This approach is to be situated against an opposing, supposedly orthodox ‘geometrical’ approach to spacetime structure, as encapsulated in the works of e.g. Janssen (2009) and Maudlin (2012). (This is not to say that either the dynamical view or the opposing geometrical view is a unified edifice, as we will see below.) The dynamical-geometrical debate has many facets, but one can take the central bone of contention to pertain to the arrow of explanation: is it the case that the geometrical structures of spacetime explain why material bodies behave as they do (as the geometrical view would have it), or is it rather the case that the geometrical structure of spacetime is explained by facts about the behaviour of material bodies (as the dynamical view would have it)? Although this debate connects with historical debates between substantivalists and relationists, it should be regarded as a distinct dispute, for reasons to which we will come.