Heinz Werner developed his theory in the first half of the twentieth century. In this period, phenomenology became one of the most important movements in philosophy. On the other hand, in this same period, empiricism—such as cognitive sciences—struggles to establish itself as the main research method of psychological functions. Although Werner’s theory of human development receives important influences from Ernst Cassirer’s theory of symbolic forms, the influence that Werner receives from phenomenology is less clear. In this chapter I explore the phenomenological basis of Werner’s theory and experiments, his work being an important step toward what could be called cognitive/developmental phenomenology.