One of the biggest criticisms lobbed against Lost throughout its run was that the writers were simply making things up as they went along, and that line of thinking continues even to this day. Now one of the show's writers has penned a blog post detailing exactly what the team had planned from the very beginning.
Javier Grillo-Marxuach, who wrote for Lost's first two seasons, dropped a massive, 17,000 word account of the early days of Lost on his blog. A lot of it reiterates details we've heard before regarding the creation of the show, but it offers some fascinating new insights about the writers' game plan.
*SPOILER ALERT!* Grillo-Marxuach writes that on the very first day the writers met, showrunner Damon Lindelof outlined for them that the island would be the nexus of a conflict between good and evil, that it had a mysterious force at its core, and that people are brought there to play out a "primal contest between light and dark."
This is some pretty great evidence of the core of the show being planned from the beginning, as that description kind of summarizes the entire series in a nutshell. The series ended up being about people throughout history being brought to this island with a powerful force at its core, "the source," and playing out a old battle between good and evil, the battle between the protector and the Man in Black. It's not totally fleshed out, but the fact that Lindelof had that idea outlined before the pilot even went into production is pretty great evidence towards him having a solid overall game plan.
Lindelof in that same meeting also apparently pitched the idea of the Medusa Corporation, which would later be changed to the Dharma Initiative. He explained that they had stumbled upon an equation predicting the end of the world (the numbers, or the valenzetti equation). They discovered the strange force at the center of the island and came there to explore it and to conduct a series of behavioral experiments (which would involve polar bears). These experiments would in part be intended to see if there was a way to avoid the armageddon that the equation was predicting.
Also in that meeting they discussed the idea of the hatch, though it seems this was not necessarily connected to Dharma right away, and the idea that John Locke was a frustrated man whose experience in the crash would send him on a mystical journey to find his destiny. Later on the writers would pitch ideas for what was in the hatch, including that it lead to some sort of Atlantic style lost civilization, until Damon rushed in one day to declare that it contained a guy who had to push a button every 108 minutes to save the world.
He also addresses Walt, one of the great mysteries of Lost that was never quite resolved. Grillo-Marxuach makes it clear that at first Walt was unequivocally intended to be psychic, though the network executives were opposed to that idea. He said that the show ended up being vague enough about it that it wasn't clear, but that Damon in the writers room would often declare that yes, of course Walt's psychic. Later in the series it seemed more that Walt had some sort of connection to the island that certain special people have who are destined to help protect it, as reinforced by the epilogue "The New Man in Charge." Damon and the writers could have potentially changed their thinking about Walt after Season 2 and after Grillo-Marxuach left, having a better idea of this connection to the island. But from this post it seems like when writing Season 1, the writers definitely were writing from the perspective that Walt was psychic. To this day, Damon Lindelof will not give further insight into the mystery of Walt except that they probably would have done more with him if the actor didn't age quicker than made sense for the show's timeline, forcing them to write him off.
The rest of the essay paints a pretty fascinating narrative about the creation of the show and about a constant struggle with the network throughout the first season. He also talks about the idea that along the way JJ and Damon had to essentially flat out lie to ABC, promising that the show would be serialized and grounded in reality and that a viewer would be able to pick it up anywhere like a CSI type show. Oh how wrong that would end up being. The network was apparently totally opposed to any sort of weird, sci-fi elements, even forcing them to not introduce the Others until later in Season 1 because they didn't want the writers to get into the mysteries of the island so early.
One last really interesting element he brings up here: in terms of "what" the island is, Damon and the writers apparently had a very specific answer to that. He says there was a "concrete reason that we openly discussed on several occasions about why the island had an exotic source of power in its core." Before this, fans just kind of assumed that the "source" of the island was like the force in Star Wars: just a part of the universe that you accept as being how this world works. But apparently there is an actual reason that the island has this force and is the way it is, which is so intriguing. We'll probably never find out what this is, as Damon Lindelof has been pretty firm about not confirming any fan theories (except for putting to bed the idea that they were dead the whole time.) But could there be any hints towards what they had planned within the actual series? Time to fire up those fans theories all over again, Losties. We can figure this thing out.
Overall then, Grillo-Marxuach's essay goes to show a pretty solid game plan for Lost from the very beginning, with Damon Lindelof outlining to the writers the overall "point" of the show and the island from the beginning. The writers were openly discussing "the source" all the way back before the pilot, even though this is something that wouldn't really be made explicit until the final season. Of course the majority of the show was improvised as the series progressed, just like every TV show is written, but the criticism that the writers had absolutely no idea where anything was going, based on this blog post, seems to be pretty unfounded. So to anyone still lobbing that criticism at Damon Lindelof and at the series: you can let go now.