While the clinical infant is not a real person, it is a theoretical construction of a number of persons and in many ways is the most important "person" of The Interpersonal World of the Infant. Early in the book, Stern sets up a contrast between the two central theoretical constructs of two fundamentally distinct perspectives on infant psychology - the developmental psychologist's perspective and the psychoanalysts' perspective. Stern worked as both a clinician and a developmentalist and seeks to unify the two perspectives.