The only classification that he knows is the one that was already common currency at the time of Willis: frenzy, invariably accompanied by inflammation and fever; mania, where fury is not a sign of the brain being affected; melancholia that differs from mania in two ways 'firstly, in that melancholic delirium invariably has a single object, known as the point of melancholy, and secondly in that delirium is always pacific'.