"North American Federation" and serves its interests. Later, Matt's mentor in the Patrol makes him understand that if such an unlikely dilemma should arise, his commanding officer would lock him in his room rather than expect him to participate in the attack. The mentor uses this scenario to force Matt to confront the personal and political issues involved in the institutional control of atomic weapons in a more mature way. Written almost a decade before the American Civil Rights Movement, and at a time when non-white characters were almost entirely absent from science fiction, the book also explores the theme of racism, both literally, in discussions about the cosmopolitan racial makeup of the (all-male) Patrol, and metaphorically, in its description of conflict with the Venerians. Venus is described as intensely hot and (incorrectly, as is now known) swampy, but habitable. The Venerians are at first thought to be primitive, but it is later revealed that they have a high level of technological sophistication, though developed along radically different lines than that of humans. There is also a subplot revolving around the issue of what it means to be a good soldier. Discouraged by the intellectual demands of his Patrol training, and attracted to the glamor and esprit de corps of the Marines, Matt requests a transfer, but is dissuaded by his mentor. The mentor, dividing human motivations into three types, explains that the Patrol, which has the responsibility of holding the ultimate weapon and keeping overall peace, is manned by a certain sort of person, the man of ideals (its motto is Quis custodiet ipsos custodes?). In contrast, the Marines, the service branch which deals with ordinary military affairs, are trained to prize unquestioning loyalty and bravery as the highest ideals, and are deliberately recruited from the type of person who seeks glory and excitement. Matt belongs to the former category. The Merchant Service, by implication, is for a third category, those motivated by economic concerns — which is where Burke fits in. The novel contains an early description of a mobile phone: The phone "was limited by its short range to the neighborhood of an earth-side [i.e. terrestrial] relay office". A cadet avoids having to talk to his family while traveling by packing his phone in luggage. Critical reception Surveying Heinlein's juvenile novels, Jack Williamson characterized Space Cadet as "a long step forward. ... The characters are stronger [and]