Lord Dorwin is a Chancellor of the Galactic Empire. He visits the Foundation to help out their negotiations with Anacreon, and fancies himself quite the archeologist. His task? To pull a Prometheus and discover the origin of humanity.
Dorwin has two roles to play in "The Encyclopedists." First, he shows us that the Empire is stagnant, since his version of the scientific method is to read the works of old scholars and compare their ideas. No original research for this interstellar Indiana Jones. He's content to rest on the accomplishments of the past. (We see this later in characters like the tech-man and Jorane Sutt, but we discover it first in Dorwin.)
Second, Dorwin represents the power of an Empire in decline. The old Empire would have stood up to Anacreon without a second thought, but not now. Instead, Dorwin uses his political silver tongue to wiggle his way out of responsibility. But his words cancel each other out, meaning his promises are worth about as much as the hot air he speaks them with.
If Dorwin is the Empire's representative, then it's no wonder we're not feeling too good about the state of the galaxy.
Anacreon's envoy to the Foundation, Anselm wants to place a military base on Terminus, dividing the land for Anacreon's nobility and securing a prime strategic spot in case war should break out. Although we never see it firsthand, we can glean from his stories that he has a violent temperament and thinks war is pretty rad.
In "The Encyclopedists," Anselm's desire to colonize Terminus is an obstacle to the fledgling Foundation and starts the first Seldon Crisis. And thanks to his violence-loving nature, we can see him as a foreshadow of Wienis, Hardin's main antagonist in the novel.
Lee is Hardin's right-hand man. He organizes the coup d'état and successfully wins the Foundation for Hardin. He works for Hardin all the way up through "The Mayors," but we never see him actually do much of anything. He's more a behind-the-scenes kind of guy if you catch our drift. (And they're the ones you have to watch out for.)
All these guys are members of the Board of Trustees overseeing the Encyclopedia Committee, and they have one purpose in life and one purpose only: complete the Encyclopedia Galactica. Naturally, they disagree with Hardin on almost everything. It ends up sounding something like this:
Hardin: Should the Foundation involve itself in the politics of the Four Kingdoms?
Hardin: Should the Foundation use its science to strengthen its position in the universe?
Hardin: What color should we paint the walls?
Board: Ugh, are you really going with that shade of eggshell?
Bor Alurin is the one and only psychohistorian at the first Foundation. He was the teacher of one Salvor Hardin, whom he taught basic psychology and psychohistory. There's a hint that he didn't train Hardin as well as he could, for fear that his student would work out Seldon's Plan and botch the whole operation with his foreknowledge—but we can't say for sure.
We don't know much about Alurin except that he went and died between the "The Psychohistorians" and "The Encyclopedists." But we thought we'd include him here all the same. Maybe he'll make for a tricky pop quiz question or something.