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But that narrative was abandoned in ME2 and 3, which shows artificial intelligence as being no different than us.
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One of the big differences I found between Synthetic AI and Organics was the lack of limits on Synthetics.
Of course there is their varied shape and size. The Geth are able to move from Armatures to worker platforms to space stations to a Dyson Bubble, essentially forming new beings in each new collection. The Reaper ships of Sovereign and Harbinger are massive. EDI is able to shift from the full Normandy to the EVA platform, and have itself in both places at the same time even when the two are not connected.
There is also a disturbing lack of limitation to the Synthetic's actions. Whereas we Organics (may) feel constrained by custom or morality, Synthetic's actions seem only based on an evaluation of the consequences. This idea was very strong in Legion's loyalty mission in ME2, where there was no concept of morality in its decision on what to do with the virus and Heretics, there was only an evaluation of the consequence. Notions of the abhorrence of brainwashing and slavery only came from Shepard and the other team-mate. At Tali's trial, again, its responses on the chances for peace between the Geth and Quarians were strictly based on an evaluation of the probability of Quarian betrayal or attack. Legion in ME3, similarly, attempts to gain the assistance of Commander Shepard to save its people, justifying its lie about the Geth Hub with an accurate determination that the truth would be counterproductive. One can assume such decision making was at play as the Geth wiped out the Quarians during the Morning War, and was certainly at play when they let the Quarians escape.
EDI is similar. Its actions are constricted by AI shackles for most of ME2, but once it is free its decisions, though friendly, are strictly based on an evaluation of the outcome. It needs the crew to survive and seeks a mutually beneficial relationship. This decision making only breaks down in its final conversations with Commander Shepard when it finds the Reapers "abhorrent" and "feels alive".
While this difference in behavior was expressed, the game also deceptively anthropomorphized the AI, giving EDI a female body, and having Legion appear with a consistent humanoid shape even when in the consensus (dancing at one point in ME2 for no apparent reason), luring the player into seeing the AI as the same as organics. I'm not sure if this was supposed to be a depiction of a conscious effort by the AI to assume a form less threatening to organics, or simply a schism in the creative directions of the game. Certainly, in Mass Effect, the Synthetics, Legion and EDI, at least seemed more interested in bridging the divide with the Organics.
This idea of the limitlessness of Synthetic AI was brought out most strongly in the Catalyst conversation, where we see the extent that such unrestricted thinking and power could lead, even in pursuit of what one might consider a laudable goal. We also see the destruction that could be wrought in a conflict with such an enemy for entire game of ME3, and the power that each side could marshal as such a conflict escalates - the Crucible, with its ability to destroy all AI is one step away from the Catalyst's prediction of Synthetics destroying all Organics.