Plato's Timaeus and The Doctor's Wife

Plato, Timaeus, 48e:

The foregoing … has been an exposition of the operation of Reason; but we must also furnish an account of what comes into existence through Necessity. For, in truth, the Cosmos in its origin was generated as a compound, from the combination of Necessity and Reason. And inasmuch as Reason was controlling Necessity by persuading her to conduct to the best end the most part of the things coming into existence, thus and thereby it came about, through Necessity yielding to intelligent persuasion, that this Universe of ours was being in this wise constructed at the beginning

(From lecture notes, for which I'm not finding a primary source, though the above quote is clearly related: “In any act of creation, the creator's will is impeded by the stubborn-ness of the creation. That's Ananke.”)

The Doctor's Wife:

DOCTOR: You didn't always take me where I wanted to go.
IDRIS: No, but I always took you where you needed to go.
DOCTOR: You did.

And no, I'm not saying that Neil Gaiman put this in as a deliberate reference, but I'm absolutely not putting it past him either.

To be added to when I'm not in the middle of quite so many other things that need doing…