 Later writings develop the argument of “Reflex Arc”, namely that complex behavior cannot be explained by building up simpler constituents. “Acts” provide a better starting point, of organisms in environments (HNC, MW14: 105). Acts are transactional: we act with and on things, in contexts, amidst conditions. Acts are fundamental to understanding behavior because they are selective. By directing movement and organizing situations, they manifest interest. This combination—of selectivity and interest—make activities meaningful. For example, our ancestors acted selectively regarding how to satisfy instinctive hunger; such selectivity created the conditions for a more elaborate interest in the taste of food, and, much later, in dining customs and cuisine.