effective means of making peaceful contact with new spacefaring species, which allows the series to expand its range of plots, characters and locations. White said that The Troubles in Northern Ireland induced him to write about the sort of world he would like to live in, and that he disliked war and militarists. As a youth he wanted to become a doctor, but had to go out to work. Hence he relied on epidemics and natural disasters to provide the conflicts that stories need to make them interesting. He credited his wife, who was an intensive care nurse at the height of The Troubles, for advice on medical details and for pointing out how padres often did more good than doctors for disturbed patients, which inspired The Genocidal Healer. Challenges of inter-species medicine Sector General was founded to promote inter-species harmony, and therefore all medical staff must be prepared to treat beings with very different physiologies and behavior patterns, and sometimes with environmental requirements that would be lethal to staff without suitable protection. The hospital uses a four-letter system to assign patients to wards that provide suitable environments, a classification technique used earlier by E. E. "Doc" Smith's Children of the Lens. White's Star Healer introduces the classification "FOKT", which is regarded as an in-joke on the name of the Glasgow science fiction club Friends of Kilgore Trout. Early on, it was learned that diseases were species specific, so there was no danger of a disease or virus spreading to other races and potentially causing a pandemic. Extreme care is still taken, as there only has to be single instance of this not being the case to have deadly consequences. When necessary physicians, surgeons and pathologists download information about patients' species into their minds from "Educator tapes", recordings of the memories of great practitioners in the appropriate species. However, in addition to medical knowledge, the educator tapes also capture the personalities of the medical experts who recorded them. Thus having an educator tape active threatens the recipient with multiple personality disorder. The new personality is from a vastly different species, often with very different behavior codes and sexual preferences, and, to make matters worse, the donors were often very dominant personalities. The mildest symptom of such conflicts is a running gag in which users of these tapes are often seen in the Sector General's cafeteria, eating a bland-looking sandwich with