Senses of the self is the main theme in the book. Daniel Stern's "Self Psychology" is the central idea of The Interpersonal World of the Infant. Stern's goal is to make sense of subjective infant experience. His method is to understand subjective experience in terms of senses of self. Senses of self tie together and unify experience; they are also able to be experienced themselves. Sense of self allow the mind and brain to draw together disparate sensory modalities and their information and create an equilibrating system of affect, perception and action.