Random ramblings and thoughts to follow:
In Trespasser, you learn that he views the modern population as most people would view tranquil - less than people. He believes something intrinsic and fundamental to being a full person is now lost to the elves, but I think he regrets what happened to the ancient dwarves as well. We don't know what happened, but in banter with Varric, he argues with almost as much fervor as about the elves that something was lost to them that makes them less than they were in a fundamental way.
I would assume this is a greater connection to Titans/The Stone that they must have had at one point, just like the elves and the fade. This may have also given dwarves their own magic, which would be another reason Solas is upset about Varric not caring about The Stone.
He says "Dwarves are the severed arm of a once mighty hero, lying in a pool of blood, undirected, whatever skill at arms it had gone forever. Although it might twitch to give the appearance of life, it will never dream."
That seems exactly like what he thinks of the rest of the world being sundered from the fade. Sometimes they seem to mirror what he sees as being truly alive, but it's just an imitation.
Codices also describe an event in the past that "Split the dwarven race in two." Perhaps this is because the Titans are dormant, or too many have been killed? Are the Titans and dwarves both seen as dwarves by the writer of this entry, as they're both "children of The Stone"? The mural of a Titan being killed does resemble a dwarf in shape. That mural depicts Mythal destroying a Titan so the ancient elves could make use of their demesne, which basically means land or domain. In this case, it means lyrium, and according to the Inquisitor, something else that is unclear.
Also on the mural has someone (presumably Solas) talk about how the greed of the Evanuris threatens the elves, but could he also simply not want the dwarves to lose their connection to the Titans and The Stone? He might no longer see them as people if they did (and they did). Oddly though, Mythal, the only Evanuris he admires is the one destroying the Titan.
Back to the above quote: If the dwarves are supposed to be connected to the Titans, they are almost literally "lying in a pool of blood." The Titans' blood. Maybe if he destroys the veil, it will wake the Titans and reconnect the dwarves to them, and in Solas' eyes, ascend them to the prestigious rank of Person. Maybe that's a nice side-bonus to restoring the elves.
Lastly, does anyone now find it rather amusing (in a macabre sort of way) that Solas' analogy is a severed arm? 
Retour en haut
And considering it was Weekes who wrote him, and he's the new lead, I think he had this planned for a while. He does things like this all the time (like there apparently being a golden prosthetic left arm in the golden nug room at Darvaarad). Then of course there's the Skyhold surgeon who says "When in doubt, amputate!" Like... really? Now you're just rubbing it in our faces! 
