Theorists seeking evidence of moral cognition – whether in human infants, nonhuman animals, or any other population – would benefit from a minimalistic description of what moral cognition is. However, such a definition has proven elusive. Some argue that debates over the existence (or not) of moral cognition in various populations turn on unresolvable semantic disagreement over how to characterize the moral domain. I acknowledge a semantic dimension to some disputes and identify another problem: Often, while sidestepping semantics, researchers rely (...) on logically circular operationalizations, defining moral cognition in terms of elements that are already implicitly understood to be features of moral cognition, while failing to answer the question of what makes these features, or their combination, uniquely moral. The present article proposes a single solution to both problems. The issue of semantics is addressed by the identification of a naturally emerging and distinctive cognitive modality that is necessary to all definitions of moral cognition. The problem of circularity is overcome by a reduction of moral cognition to elements that are, in themselves, nonmoral. I call this distinctive combination of nonmoral elements the “molecular” structure of moral cognition. (shrink)