Disinhibition—

     Among the principle functions of the brain's more recently evolved structures is the inhibition of certain behaviors. Thus, many injuries to these structures result in the disinhibition of the "corresponding" actions.

     —But evolution is blind to the psychological cost of this psychic tension. She sees only outputs, not processes. The same level of external activity implies much more internal force for a human than for the "less evolved" organisms. The soil of consciousness is continuously renewed by the ashes of these dynamic contradictions.