Story structure
Mad scientist
A stock character: a scientist with unusual or unsettling personality traits, usually in the taboo or hubristic nature of their experiments.
"The mad scientist, also known as the mad doctor or mad professor, is a stock character of a scientist who has unusual or unsettling personality traits, usually in the taboo or hubristic nature of their experiments." The type is flexible: he "may be villainous (evil genius) or antagonistic, benign, or neutral; may be insane, eccentric, or clumsy," and characteristically "fails to recognise or value common human objections to attempting to play God." The prototype is Victor Frankenstein in Mary Shelley's 1818 novel; Wells's Doctor Moreau "has isolated himself entirely from civilisation in order to continue his experiments," and Rotwang in Metropolis (1927) "brought the archetypical mad scientist to the screen."
For novelists the figure is consequence given a face: where a story's science can do anything, he is the person who does it, which is why questions of cost and limit keep arriving in how to write science fiction. He also works as a foil for the disciplined protagonist, method set against method, and his hubris should cost him; an unhinged genius who is always right is not a character but a plot vending machine.