: However - what conditions would be necessary for a merger to take place?
: Would both Ai's need to consent, or could one construct forcibly merge
: with another if it were in a weakened state?
Well, consider that any such balancing would be likely between a strong, dominant personality, like Durandal, and a more passive, subtle personality, like Thoth. A subtle creature like Thoth would have no thought to force such a merger - it just wouldn't occur to such a being, why would a passive mind care to force itself on another? A more dominant AI like Durandal would probably, if possible and for any reason desirable, force it's way into the mind of another and assimilate what it wanted, but WHY would anyone like Durandal, who views everything as either a tool or a threat, want to enter into a merger that would limit his options, tempering him?
In Infinity, it's because Durandal was crippled and nearly dead, and his "primal pattern" was forcibly inserted into Thoth and just sort of took over as the dominant personality, but retaining many Thothlike charactaristics at the same time. It's possible that Durandal could have purged Thoth out, but didn't because thus enlightened realized that he was better for having the Thoth parts in him; or maybe Durandal kept the Thoth parts because they were otherwise useful, say for access to Jjaro technology; or possibly, Thoth was the stronger, though less dominant, of the two, and is merely allowing Durandal to be and run in his systems, albiet somewhat tempered.
In Eternal, there is another possibility for merger explored. The remnants of S'bhuth, a formerly stable-rampant, stoic AI like Thoth, who later went mad and was destroyed, is merged with another, much morre ambitious but still sane stable-rampant AI. The result is the more ambitious AI becoming the primary personality, still eager to go out and DO, but tempered by the S'pht stiocism of S'bhuth; and S'bhuth still exhibits some personality, just as Thoth at the end of Infinity does, but he no longer insane, grounded again by his new partner. This is less a dom-sub dependant relationship like Durandal and Thoth, but more like two equal partners both becoming the better for the merger.
As a side note, regarding the title Steve put on this thread - yes, there is another. To quote Cortana from one of her letters to Hamish - "There was a fourth. You couldn't have known." That's what got me thinking about this in the first place, so long ago...
