In the original "Doctor Who", the Time Lords were the Doctor's mysterious, near-omnipotent superiors. In the current revived series, the Time Lords no longer exist, having been destroyed by the Doctor in the last great time war. Why was it so important for the new series to completely exclude the Time Lords?
Here's one possibility that I stumbled across recently. Here's a description of Jonathan Swift's Laputans from "The Closing of the American Mind" (pp. 294-295), by Allen Bloom:
On the Flying Island [of Laputa] the men have one eye turned inward, the other toward the zenith. They are perfect Cartesians -- one egotistical eye contemplating the self, one cosmological eye surveying the most distant things.
Bloom further quotes Swift:
Another peculiarity of these men is described by Gulliver as follows. "What I chiefly admired, and thought altogether unaccountable, was the strong disposition I observed in them [the Laputans] toward news and politics, perpetually inquiring into public affairs, giving their judgements in matters of state and passionately disputing every inch of a party opinion. I have indeed observed the same disposition among most of the mathematicians I have known in Europe, although I could neve discover the least analogy between the two sciences."
This is a dead-on description of the Time Lords. The Time Lords live on a planet named Gallifrey that is supremely well-defended from attack by an impenetrable force field ("the Flying Island") . The Time Lords are masters of space, time, and transdimensional engineering ("They are perfect Cartesians", in the geometrical sense). The Time Lords keep watch over threats to the spacetime continuum as a whole and draw their power from an artifact called the Eye of Harmony ("the cosmological eye surveying the most distant things"). The Time Lords are also naturally telepathic ("one egotistical eye contemplating the self") and, of course, are not entirely immune to meddling in the affairs of other species ("perpetually inquiring into public affairs", etc.). The Old High Gallifreyan language was even written using mathematical symbols ("I have indeed observed the same disposition among most of the mathematicians I have known in Europe").