Arthur was a member of the Marge Simpson's family.
He was only mentioned once, in the fifth season episode, "The Boy Who Knew Too Much" by Marge, who told Bart that his uncle used to have a saying, "Shoot them all and let God sort them out," until one day he put his theory into practice, and "it took 75 federal marshals to bring him down."
Numerous flashback episodes show Marge, Patty and Selma were the only children of Clancy and Jacqueline Bouvier, including "The Way We Weren't" set when Marge was a child, so it is unclear if Arthur was her brother or a more distant relative like a granduncle. Arthur seems to be a source of shame and embarrassment to the family. After Marge finished telling Arthur's story to Bart, she said, "Now let's never speak of him again."
Shortly afterward, she briefly alluded to him (although not by name) to Bart when cautioning him about listening to voices in his head, as he did on one December morning (implied to be the same day he decided to put his saying into practice). The references to voices inside his head imply that he was mentally ill, possibly schizophrenic.
Appearances[]
Episode – "The Boy Who Knew Too Much" (mentioned)