On the issue of the second inutteral, from TTT p.380:

With three voices he sang, one utteral pitched to the world and two inutterals directed to the ground. What had been an ancient Cant of Calling became something far, far more...A Cant of Transposing.

So it's not about refining the purity (although surely that sort of thing is possible), but about creating a new meaning entirely.

I always think of the soul as possessing a sort of thin boundary between the Outside and the mundane, with utterals and inutterals acting as varying sorts of portals set on either side of the boundary. 

Serwa explains to Sorweel:

"The Nonmen have invoked Niom," she said. "An ancient ritual."

...

"The ancient Nonmen Kings found Men too mercurial," she explains, "too proud and headstrong to be trusted.  So in all their dealings they demanded hostages as a guarantee: a son, a daughter, and a captive enemy.  The two former as a surety against treachery.  The latter as a surety against deception."

Ramachandran is fantastic.  That documentary posted earlier led me to the corresponding book, then his others.  His whole professional focus is on the oddest perceptual effects he can find.  Read Montague, another neuroscientist, wrote Why Choose This Book, which is a book about decision making from the perspectives of computer programming, energy efficiency, and evolution.  That one will cause rapid and deep reevaluations of your self. 

Steven Pinker's The Blank Slate is along a similar vein, tackling the myths of the blank slate, noble savage, and ghost in the machine from an evolutionary psychology view.

I found this forum the usual way, looking for more SA information.  Prince of Nothing was suggested on another board in a thread about 'what to do while you wait for TWoW', and one quick torrent away, I read it on my phone at work for a few days.  Plowed through TWP, then halfway through TTT I realized I should just buy these books.  Read the rest, found this place which made me reread TTT, then the entire series again, and now I sometimes open up a favorite scene.  I love world building in any kind of media, and this place where reason and magic completely overlap just presses a needle right into that love.

(And then he shat down a pit.)

So now that I'm caught up on most of this forum too, I feel like it's cool to post my own brand of crackpottery.  And here's perhaps my favorite aphorism (I love Ajencis, but Memgowa had a way with things):

"Souls can no more see the origins of their thought than they can see the backs of their heads or the insides of their entrails. And since souls cannot differentiate what they cannot see, there is a peculiar sense in which the soul cannot self-differentiate. So it is always, in a peculiar sense, the same time when they think, the same place where they think, and the same individual who does the thinking. Like tipping a spiral on its side until only a circle can be seen, the passage of moments always remains now, the carnival of spaces always sojourns here, and the succession of people always becomes me. The truth is, if the soul could apprehend itself the way it apprehended the world -- if it could apprehend its origins -- it would see that there is no now, there is no here, and there is no me. In other words, it would realize that just as there is no circle, there is no soul.