Along with supernature and science, there is one other major source of horror movies disorder: the human psyche, most commonly homicidal psychosis. Unlike 'mad' scientists, horror-movies madmen are not visionary obsessives, glorifying in scientific reason as they single-mindedly purse their researches. They are, rather, victims of overpowering impulses that well up from within; monsters brought forth by the sleep of reason, not by its attractions.