This is an important work which will be widely read in both psychoanalysis and developmental psychology. Stern's perspective is based on recent research which indicates a strong biological preparedness for social interaction in the human infant. Biological preparedness, however, means that it is all the more crucial for us to focus on the infant's inner experience to understand development, and the problems of tracing continuities in the midst of change. The scientific argument for a psychology of experience is bold enough during a time of life when the child cannot talk to us, but Stern goes further. He stretches our minds to consider not only the subjective world of the infant, but also the intersubjective world involving infant and caregiver. The book's title is well chosen.