This article discusses binary, or dichotomous, thinking as it develops in normal classification, in pathological splitting, and in shifts of cultural awareness such as that from Classicism to Romanticism. It relates these to states of subjective and objective self-awareness as induced and regulated by the early parental environment. A number of clinical examples demonstrate how pathological splitting may arise and how the therapeutic process works to alter dichotomous thinking and raise it to higher levels of integration. It also suggests that a similar process of integration can take place over time in our historical understanding of cultural paradigm shifts.