As with many definitions, there are tradeoffs to be made between utility and accuracy. The more limited form of definition has uses as a shortcut to describe a

As with many definitions, there are tradeoffs to be made between utility and accuracy. The more limited form of definition has uses as a shortcut to describe a certain subset of people, but if you look at disability more broadly you can get a fuller sense of what disability is. To give another example, consider the definitions we use to describe sexual preference. This article on sexual fluidity gives some good examples of how the way we describe sexual preferences may be fine for many, but misses the bigger picture: http://nautil.us/issue/41/selection/beyond-sexual-orientation http://nautil.us/issue/41/selection/beyond-sexual-orientatio... I found this passage about bisexuality from the article particularly interesting, describing how openness to bisexuality was suppressed because it didn't fit into the more limited but easier to understand narratives that reflected mainstream thinking about sexual preference at the time: "Robyn Ochs, who came out as bisexual in 1982 and has been campaigning for bisexual rights ever since, remembers some gay marches before the mid-1990s as unwelcoming. “Lesbian women thought that we were sleeping with the enemy,” says Ochs. Dawne Moon, a sociologist at Marquette University, explains that some gay people felt that bisexuals were watering down their message. Any kind of sexual variability outside of homosexuality would threaten the narrative of the gay movement, says Moon. That narrative revolved around same-sex attraction being as authentic and fixed an orientation as heterosexuality. The scientific practice of the 1960s through the early 1990s reinforced this message. Some researchers blatantly denied the existence of bisexuals. In 1956, the American psychoanalyst Edmund Bergler described bisexuality as “a state that has no existence beyond the word itself” and an “out-and-out fraud.” Other researchers used terms like “true homosexuals” in their studies. It was common for academics to lump bisexuals and homosexuals together. Even many school and college textbooks did not quite recognize bisexuality as a possible sexual orientation until about a decade ago. Bisexuality was seen to be a phase some people go through before identifying as heterosexual or homosexual. Kenji Yoshino, professor of constitutional law at New York University School of Law famously called this phenomenon “bisexual erasure” in an essay he wrote in the Stanford Law Review in 2000. “It is as if self-identified straights and self-identified gays have concluded that whatever their other disagreements, they will agree that bisexuals do not exist,” Yoshino says." Why do I bring this up? It's to point out that broader understanding of human variability has its place, even if it makes people who prefer neater definitions uncomfortable. It's the same with disability, it takes on many forms, and although shortcuts/simpler definitions have their place it's worth recognising that variability, even if that makes reasoning about it harder to do.