A new taxonomy of functions distinguishes between content functions and logistic functions to implement conscious activities. On the basis of this classification the repertory of consciousness comprises neuronal programs in four different content domains, providing perceptions, memories, evaluations and volitional acts (Pöppel, 1988, 1989a). Neuropsychological evidence suggests that elementary functions within these domains are represented in a modular fashion. This evidence comes from studies with patients who have suffered specific injuries to the brain. It can be demonstrated that elementary functions are lost if circumscribed regions of the brain are no longer functional. Thus, the interindividual constancy of a loss of function proves the existence of neuronal modules which under normal circumstances provide these functions. These content functions provide the material of conscious activities.