We explore folk theories of sound judgment across two cultures, with a particular focus on the distinction between rationality and reasonableness and how people apply these concepts in a range of social and non-social contexts. Four studies using English-speaking samples in North America (Studies 1-3; N=1,826) and a Mandarin-speaking sample in China (Study 4; N=659) examine spontaneous descriptions of characteristics of sound judgment, preferences for and perception of agents in different social contexts (varying in demands for rule-based vs. holistic approaches to decision-making), and categorization of non-social objects. People spontaneously considered both rationality and reasonableness as central features of sound judgment and yet assigned unique attributes to these standards when mapping concept networks. In experiments, people favored rational agents for contexts demanding analytic reasoning and reasonable agents for contexts demanding interpretive/holistic reasoning. Moreover, across cultures, people used rule-based categorization for rational judgment and overall-similarity categorization for reasonable judgment of non-social objects.