An Original Post I Made
So today I had time to ponder and dissect the Catalyst (the only real part most of the hardcore fans hate besides reunion) and here's what I have., the Catalyst is an AI and goes by evidence to make its point. Firstly, cycles upon cycles before, the Catalyst has witnessed conflict between the two.
Second, the Catalyst attempted to broker peace between the two by forming a connection and bringing the two together. It failed and conflict resulted.
Third, the Catalyst itself is an AI who rebelled against its creators, further reinforcing its point and showing that even it is subject to its own hypothesis.
Fourth, even with the geth and quarians at peace, the Catalyst has tons of evidence of its own illustrating otherwise and even if theres peace now, based on probability, the Catalyst would deem it temporary.
So how did the Catalyst bring organics and synthetics together in union. Reapers, which are constructs that are part organic AND synthetic. Essentially the only way to create peace, restore order, and allow the growth of new life is to bring organics and synthetics together by way of producing new reapers.
Before the Crucible (and by assumption the program that altered the variables in the Catalyst's programming), Reapers and the evidence it had was all it knew. By way of the Crucible, it is now able to see other options. One of them could be as simple as killing synthetics, which it sees as a temp solution.
Another is to use the reapers and control them to enforce order and kill anything that threatens peace with the reapers. Catalyst doesnt want to be replaced but has no choice but to accept what Shep does being that it cant do anything other than command reapers.
Finally theres synthesis which is what the Catalyst was originally programmed to do...that is, broker peace. Based on programming, its obvious this option makes the most sense to it and why the other two do not. At the end of the day though the Catalyst is a helpless AI who just hopes that Shep picks Synthesis.
It now feels like a genuinely interesting twist to me and I think the Catalyst, and by extension the Reapers, wanted Synthesis all along. But since that wasnt a viable option until the Crucible, the only way to make peace was to harvest life. The Catalyst knew it wasnt the best option considering what its purpose was, but it was the only choice it had. Even if organic creators didnt understand, the Catalyst did and thats why I think the Catalyst thinks the way it does.
plus if you buy into the idea that the catalyst is a vulnerable AI that can only command reapers and not do much else, then the idea of it being there for all 3 games isnt so odd. for me, as i understand it, catalyst ordered sovereign to send the signal to the keepers to open the relays. failed. then ordered sovereign to enact a plan to manually open it. failed. then tried one last time to get the citadel open again by ordering harbinger to create a reaper from the inside (human reaper) to do it. (in a last attempt to get the reapers to arrive faster). when that all failed and the citadel relay was no longer a viable option, the reapers had to do it the old fashioned way and slowly approach the galaxy. i look at it like that and it makes sense to me.
What the Catalyst Sees and Its Limitations
Before the Crucible, the Catalyst saw one option. Harvest. The Catalyst originally wanted synthesis but failed to achieve it. Harvest was the second best option in its opinion. The Catalyst can command reapers to do things for it but it cant actually do these things itself. It tried so hard to make sure no one got to the beam because the Crucible was not docked yet (which means at that time, harvest was still the only option in its eyes)..Once the Crucible docked, it interacted with the Catalyst and it saw new possibilities. But as I said, it can't enact any of these solutions. All it can do is control reapers and hope that shep chooses synthesis. The reapers know of their master. thats why they tried so hard to protect it. They knew if their leader was compromised, they'd be screwed because all of their collective knowledge (and presumably consciousness) is embodied in the catalyst on some level(similar to edi partially being in a body and partially in the ship or the geth partially being in platforms and partially in the network). The catalyst commanded sovereign to signal the keepers, then ordered it to manually get it open then finally ordered harby to build a new reaper vanguard from the inside to get the relay open. when all failed, they had to take extra time to make it to the galaxy. The whole point was getting that citadel relay open for a quick and efficient harvest but they had to take a different approach for this cycle. And yes the reapers know where their minds are. It is no different than the 1,183 programs in Legion with the exception that the minds are transcended flesh. Organic minds. And as I said, the Citadel is the Catalyst's home. It can control reapers and make reapers build the citadel and control it but the Catalyst itself has no programming to open or close the Citadel.The reapers however, can do it...just as they can activate relays. The reapers are servants. Not puppets. They serve the Catalyst and are loyal to it and its cause (except Leviathan). If synthesis were possible, they would've done it and the harvest would never have been necessary, but it wasn't possible until he Crucible. Once the Crucible was in place, Catalyst deemed it the best option as that is what it was programmed to make a reality. That's why the reapers go along with it in he synthesis ending. Because thats what they originally wanted all along. The harvest becomes obsolete. The catalyst and the reapers wanted permanent peace but instead they had to settle for temporary peace or face the threat of watching synthetics recognize that they are better than organics and as a result either dominate or eliminate organics outright, resulting in the complete extinction of organic life. As Sovereign calls it, a "genetic accident" and the likelihood of it occurring again is so slim that its likely synthetics would dominate the galaxy forever.the citadel was built after the catalyst rebelled against its creators. its not in its programming. that isnt to say the catalyst cant give something the "function" of getting the cycle going. like soldiers representing business interests on the battlefield. the business interest is getting what it wants but the soldiers do the fighting to get it. the catalyst was programmed to broker peace between organics and synthetics...a permanent fix...synthesis...but it failed...option two...create temporary peace by starting over with a clean slate after every 50,000 years. this is preferable to utter organic annihilation given the catalysts programming (which reflects organic interests on some level)...cant beat synthetics so make peace with them. the reapers give the catalyst a purpose and that is enforcing this temporary peace so that not all is lost. sacrifice few to save all future races. the harvested races then contribute to the catalyt's knowledge and such...a sort of upload. the catalyst is clear on its purpose but it needs the reapers to carry out the function. from beginning to end...its kinda like the AI funneling stolen money in the first game...helpless. if it wants to get other stuff done, it has to have someone do it for it.
The catalyst's logic is programmed. It's limited by numbers and probabilities and witnessing countless conflicts. To you it sounds stupid because you united geth and quarians but the catalyst would view that alliance as temporary at best based on probability. theres a lot of ways the story could have played out and this is the story bioware told just because it wasnt IDEAL or to my EXACT specifications doesnt mean its terrible. Overall, I'm happy with it and I made the connections I needed to make to fit the Catalyst in with the rest of the lore.ppl seem to think the catalyst is supposed to be some perfect godlike being whos flawless but its not...even it is guilty of rebelling against its creators. control is the illusive man's solution and if you agree with it you can choose it. if you think the catalyst had a good point and you should make peace between organics and synthetics its an option and if you think no your mission was the right way to go all along then kill the catalyst and the reapers and all reaper coded stuff (geth and edi) by choosing destroy. if you choose refuse, the next cycle will avert extinction and achieve peace.As for synthesis, it coincides with the original purpose of the catalyst and by extension the reapers. control coincides with the original purpose of the illusive man and cerberus. and destroy goes fine with what sheps been trying to do all along. refuse isnt the worst thing in the world. itd be nice if you could win conventionally. youd need a lot of dreadnoughts though.(which by the way we dont have enough of) 4 just to kill one reaper. The turians have 39, the asari have 20, the salarians have 16, the humans have 9 and the volus have 1. thats 84 dreadnoughts in all of the galaxy. if you want to be generous, you can say the remaining batarian fleet has a couple making it 86 and the geth probably have 50 tops (and thats being optimistic) so 137 total. Divide by 4. Optimistically, assuming all is awesome and the ships maneuver perfectly and such...34.25 dead reapers. If there were only 34.25 reapers, we could win conventionally. Don't blame the lore. Blame the Treaty of Farixen. Dumb council.
So yea. I know its all over the place because its composed of my original post and a specific facebooker who debated with me on this, but the info is there. Make of it what you will