"Indeed, for all that The Beast Below seems like the outlier of the Moffat era, it is worth making it central and allowing it to serve as its own beast below, so to speak - as the myth upon which everything else is built. This is the place where Moffat picks up the legacy of Doctor Who and declares his own spin on it.
What, then, does Moffat add to this lineage? What does Moffat propose to bring to Doctor Who’s alchemy? A story about the relationship between people and their stories. One that proclaims that when faced with a diseased and rotting story the solution is to simply tell a new one - a better one. One that rejects silence, that treats storytelling as a moral duty and its absence as a moral obscenity. And perhaps most crucially, one that is about a symbolic ascension. Because in the end, the way in which Amy saves Britain’s soul is by finally becoming a creature of narrative and fairy tale, and by embracing that role. How do you save the world from its own intrinsic evil? By being amazing, breaking the rules, and, when the narrative points to something awful, telling a different sort of story.
And so the moral heart of the Moffat era stands, for a moment, revealed - an understanding and principle we can take forward in reading everything else that he does. It is an observation that stems inexorably from the history of alchemy within the series and from the underlying imagery of this story. “As above, so below,” the injunction goes - a declaration that manipulating symbols and manipulating objects is, in some sense, the same thing. That a symbol and a thing are in some sense interchangeable.
What is the moral heart of the Moffat era? It is simple.
The secret of material social progress is alchemy."
From: The Alchemists of the Middle Ages Made Transmutation Their Main Aim in Life (The Beast Below) by Dr Philip Sandifer
(Italics mine. Read the whole thing! Especially if you want a better grasp of what Moffat does.)