P1) If a ‘brain dead’ patient shows signs of vital activity, then that vital activity must be caused by a soul.
P2) If vital activity is being caused by the soul, then the soul must be present, informing the body.
P3) If the soul is present, informing the body, then there is a soul-body composite.
P4) If there is a soul-body composite, then the patient is alive.
P5) ‘Brain dead’ patients show signs of vital activity.
C) Therefore, those patients are alive.