The science fiction genre has lost one of its greatest — and most controversial — authors. Harlan Ellison, who wrote and edited groundbreaking sci-fi anthologies, short stories, and television episodes, died at the age of 84, according to his wife, via an associate.

Ellison was born in Cleveland, Ohio in 1934, and published his first short stories in 1949, before moving to New York City to focus on writing science fiction. Throughout the 1950s, he wrote hundreds of short stories, and served in the US Army for two years. In the 1960s, he relocated to California, where he began to write scripts for television shows such as The Outer Limits, The Man from U.N.C.L.E., and Star Trek. He later served as a consultant for shows such as The Twilight Zone and Babylon 5. Ellison also worked briefly for Walt Disney Studios, only to get fired after a day when co-founder Roy Disney overheard him joking about making a porn film with the company’s characters.

Ellison was an unconventional sci-fi writer who was acclaimed for his short stories. His 1965 short story “‘Repent, Harlequin!’ Said the Ticktockman” earned him a Hugo and Nebula Award, depicting a dystopian future in which time is strictly planned out: being late is a crime, the punishment being time taken off of one’s life. (Ellison would later sue New Regency and director Andrew Niccol over their 2011 film In Time, which featured a similar premise, only to dismiss the action after watching the film.)

Ellison’s 1968 short story “I Have No Mouth, and I Must Scream” also earned him a Hugo award, depicting an apocalyptic world in which machines wage war, kill off nearly all of humanity, and torture the survivors with cruel games. He adapted the story into a computer game in 1995. Ellison was also known for his work as an editor, publishing Dangerous Visions in 1967. Aided with a generous loan from Ringworld author Larry Niven, he assembled the landmark anthology, which included stories by some of the genre’s best authors, such as Brian W. Aldiss, Philip K. Dick, Theodore Sturgeon, Roger Zelazny, Samuel R. Delany, and others.

Dangerous Visions has been hailed as a defining touchstone of the New Wave movement. Ellison followed the anthology with a sequel, Again, Dangerous Visions in 1972, and planned a third, The Last Dangerous Visions, but never completed it: Ellison noted in recent years that he still planned to complete the book. In 2006, he was named a science fiction Grandmaster by the Science Fiction and Fantasy Writers of America.

Ellison was also controversial in the science fiction community, frequently described as abrasive, and involved in numerous lawsuits against studios and directors that he believed plagiarized his work — including James Cameron for The Terminator. (The suit was settled out of court.) He also publicly assaulted author Charles Platt in 1985 at a convention, and in 2006, he sparked controversy by groping Connie Willis while receiving a special Hugo Award.

Ellison’s personality and actions complicate and diminish the groundbreaking work that he’s best known for. He leaves behind a complicated legacy, one in which he left behind a body of outstanding fiction, but which is tarnished by his attitudes and actions.