This established a geometric description of the entire category of representations of the Lie algebra, by "spreading out" representations as geometric objects living on the flag variety. These geometric objects naturally have an intrinsic notion of parallel transport: they are D-modules.
This created a geometric depiction of all representations associated with the Lie algebra, by "expanding" these representations into geometric entities residing on the flag variety. These geometric entities naturally possess an inherent concept of parallel movement: they are D-modules.