He also wrote City of the Edge of Forever, which is probably the most famous Star Trek episode (there's a random encounter in Fallout 2 that is an allusion to it). To hear him talk about it is a little sad though, because he claims it's the best thing he ever wrote, and it lost a lot of its potential being translated into a television show.

Well, to be fair TOS did bludgeon the audience with making the scripts painfully obvious. Which was foolish & unnecessary considering they were smarter than your typical audiences.

Also, Harlan Ellison is a disgruntled complainer in general. It would be fun to get a look at his original version of the story though. Searching...