Smith-Acuña illuminates the structural hierarchy, roles, and boundaries that give a system structure. The relationship between parts and wholes is both simple and profound, and particularly important in looking at systems structure. These morsels of wisdom are good examples of Smith-Acuña's grace as a systems theory tour guide: one moment she's digging deeper into the nuances among the theories, the next moment she's simplifying without dumbing down, but in a manner that is enormously...