1. Why would they change their thinking?

2. How and why would all the separate chapters come together?

3. Absolute chaos

4. Everything or nothing

5. The Outcasts no longer exist

@Saxhleel12 its something hypothetical, what if statements lore wise this would never happen but if it did what do you think would change if they changed their policies. if some of the elders were more open to change. as for the outcasts i'm saying that will a faction like the outcasts leave the BOS and follow their ideologies and refuse to compromise. I apologize i wasn't very clear about my question.

^We have seen what happened when the elders at Lost Hills were last approached regarding a debate to open up the Brotherhood, which resulted in anyone who believed so being sent halfway across the country to kill some mutants.

Hypothetically-speaking (and let's assume that the negotiations do not fall apart), this would lead to the Brotherhood revolutionized into its original form as Roger Maxson intended. An organization directly helping people rebuild civilization while open to outside recruitment. More specifically we would see the MWBoS's efforts to promote human-mutant equality on a national scale (which wouldn't mean much in New California anyway since the NCR already offer mutants protection under the law, but would bring great change to the East) and the ECBoS's drive for new research into technology now found across the entire Brotherhood. Harmful organizations would quickly be stamped out, regardless of technological might. This new Brotherhood would most likely end the WCBoS's guerrilla fighting against the NCR, as the country does provide the stability sought by BoS principle. The Circle of Steel would either cease to exist, go rogue, or adapt their ideology.

I wonder what it would do to their leadership ego. Overwhelming power or influence tends to increase the authoritarian tendencies of an organization. There has been much discussion lately about the BOS as a fascist organization here. Would the unification of the chapters confirm these discussions?

Probly happening in west virgenas sorry bad spelling in factual steel it veause help people but being weaker or being the bos what you is best

If the Brotherhood of Steel changed their way of thinking, then they would lose their identity as a faction. Where they are now is as a result (and a reaction) of multiple chained events within the faction's history which would be difficult to change without a very important reason to do so.

Just looking at Arthur Maxson's BoS chapter, you can see traces wherein the faction has kept, adopted or discarded bits of their philosophy or behaviour as a result of their unique history. One need only compare Lyons' Brotherhood in 2277 to that of Maxson's in 2287 and ask what happened to them in that time, and more importantly, what happened to Maxson, to see how events ultimately changed them and their ethos.

It is a distinct possibility with the Brotherhood that a chapter could emerge with a different line of thinking which might suit your interests more, however that would not define the whole Brotherhood.

To a large extent, chapters operate with autonomy, and so long as they do not deviate from the Western Brotherhood's (Lost Hills) style of thinking too drastically, their identities and interpretations of Brotherhood belief can vary widely. It would take a serious event (most likely located at Lost Hills) for the highest echelons of Brotherhood society to change their ideology and philosophy, and even then, there is no guarantee that geographically estranged chapters will accept them.

The Outcasts were a faction of their own that split (adopting their identity) for very specific reasons concerning Elder Lyons' leadership as of 2277. A separatist faction could spring up within the Brotherhood again, but it wouldn't be the Outcasts as we know them. At most they may be "Outcast-esque" in their attitudes or perhaps even appearance (as Brotherhood separatists would make use of robots more to compensate for their small numbers, and make themselves distinct from who they were separating from, as the Outcasts had done).

There isn't one specific way of thinking within the Brotherhood of Steel, each chapter has their own identity. Having the leadership at Lost Hills make all the decisions would be very difficult to maintain because the Brotherhood are active at both coasts, in the Midwest and possibly more locations we might see in future games.