Manuel “Mannie” Gracia O’Kelly acts as the protagonist and point of view character in The Moon is a Harsh Mistress. Like many of Heinlein’s protagonists, Manuel is an expert in the repair and maintenance of computer technologies. He describes himself as a “general specialist” who can “relieve a cook and keep orders coming or field-repair your suit and get you back to airlock still breathing” (14). Like Heinlein’s protagonist in the short story “Waldo,” Manuel relies on a variety of mechanical prosthetic arms to replace the arm he lost in a drilling accident.

Manuel is an ideal libertarian protagonist. He explains that he was “born free” (i.e. not under the control of the Authority) and he maintains his freedom by working as a freelancer rather than directly for the Authority. He is part of a family clan that lives on a largely self-sufficient homestead farm; they grow their own food and, for the most part, manage their own affairs. Manuel and his family feel contempt for the Authority, and they express this by stealing water from the Authority and actively supporting the Loonie revolution.

Manuel is a man of action who has little patience for or acumen in political organizing.