Moriarty is highly ruthless, shown by his steadfast vow to Sherlock Holmes that "if you are clever enough to bring destruction upon me, rest assured that I shall do as much to you". Moriarty is categorised by Holmes as an extremely powerful criminal mastermind who is purely adept at committing any atrocity to perfection without losing any sleep over it. It is stated in "The Final Problem" that Moriarty does not directly participate in the activities he plans, but only orchestrates the events. What makes Moriarty so dangerous is his extremely cunning intellect: