Abstract

According to Cassirer, humanity is defined by the activity of the spirit. In other places, he attempts to explain the transition from ›life‹ to ›spirit‹, but this proj- ect seems hampered by his taking spirit to be a phenomenon of consciousness. Plessner’s »aesthesiology« opens up an alternative route. He discloses the mean- ing of ›spirit‹ or ›understanding‹ by an inquiry concerning the work of the senses in the context of behavior. This paper shows that for Plessner behavior is closely related to its environment while at the same time not restricted to a biological programme.