The will is one of the three pillars of the trilogy of mind that has pervaded Western thought for millennia, the other two being affectivity and cognition (Hilgard 1980). In the past century, the concept of will was imperceptibly replaced by the cognitive-oriented behavioral qualifiers “voluntary,” “goal-directed,” “purposive,” and “executive” (Tranel et al. 1994), and has lost much of its heuristic merits, which are related to the notion of “human autonomy” (Lhermitte 1986). We view catatonia as the clinical expression of impairment of the brain mechanisms that promote human will. Catatonia is to the brain systems engaged in will, as coma is to the reticular ascending systems that promote sleep and wakefulness (Plum 1991).