The purpose of this essay is to illustrate how the phenomenon of early childhood autism may cast light on issues that are central to our Understanding Of Normal Child Development - Issues Such As The Emotional origins of social experience and social understanding, the contribution of interpersonal relations to the genesis of symbolism and creative thought, and the role of intersubjectivity in the development of self. Drawing upon philosophical writings as well as empirical research on autism, the author challenges the individualistic and cognitive bias of much developmental psychology, and argues that early human development is founded upon a normal infant's capacity for distinct forms of "I - Thou" and "I - It" relatedness. To a large degree, autism may represent the psycho-pathological sequelae to biologically-based incapacities for social perception and interpersonal engagement.