Ainsworth's description of attachment patterns in the Strange Situation is one of the best known and most enduring descriptive insights in developmental psychology. Yet attachment theorists have paid little attention to whether ABC classifications represent a true taxonomy or to mechanisms that might produce truly distinct patterns of attachment. This comment focuses on three questions. Does attachment theory require distinct patterns of attachment? How can taxonomic analysis contribute to an understanding of individual differences in attachment security? And are attachment theorists asking the right questions? The authors conclude that attachment theory is indifferent to the structure (taxonomic or dimensional) of individual differences. Nonetheless, taxonomic search methods can make important contributions to attachment study if research is broadened to include secure base behavior in naturalistic settings.