A problem of action selection emerges in complex -- and even not so complex -- interactive agents: What to do next? The problem of action selection occurs equally for natural and for artificial agents -- for any embodied agent. The obvious solution to this problem constitutes a form of representation -- interactive representation -- that is arguably the fundamental form of representation. More carefully, interactive representation satisfies a criterion for representation that no other model of representation in the literature can satisfy, or even attempts to address: the possibility of system detectable representational error. It also resolves and avoids myriad other problematics of representation, and integrates or opens the door to many additional mental processes and phenomena, such as motivation.