We perceive much of the world in terms of an action paradigm. One or more agents are seen to act on an object (physical case), another agent (social case), or both, changing either its (his or her) state, its location, or both. Action is a cornerstone of human experience-so much so that to claim someone has a knowledge of the world amounts to claiming that the individual can (1) divide the temporal sequences into appropriate segments and (2) accurately predict the conditional probabilities among the segments. On a practical level, individuals with a knowledge of the world apply suitable operators on appropriate occasions-for example, heat to raw meat, mortar to bricks, water to flour-as weIl as, in the social case, smile, frown, attack, speak, etc., on appropriate occasions. It is difficult to overestimate the degree to which knowledge of the everyday (macrophysics) world can be represented as knowledge of the causal sequences into which we parse the world.