This volume, the fourth in the Vancouver Studies in Cognitive Science published by OUP, examines the role of logic in cognitive psychology in light of recent developments. Gonzalo Reyes's new semantic theory has brought the fields of cognitive psychology and logic closer together, and has shed light on how children may master proper names and count nouns, and thus acquire knowledge. The chapters highlight the inadequacies of classical logic in its handling of ordinary language and reveals the prospects of applying the new theory of kinds to cognitive psychology, cognitive science, linguistics, the philosophy of language and logic.