In today's environment, breast-feeding represents both a medical gold standard for infant feeding and a moral gold standard for mothering. The morally charged character of this discourse makes the notion of choice in infant feeding particularly problematic and fraught with difficulty. From an historical content analysis of selected editions from 1946 to 1998 of Dr. Spock's famous child-care manual, this paper explicates the process through which the breast versus bottle discourse has shifted over the last half-century, and how these shifts have shaped the context of choice within which mothers must make their infant-feeding decisions.