I think the world would have to be an entirely different place for the roman empire not to fall. The roman empire was not that stable at all.
Politically it wasn't very stable, which is the reason for the civil wars. Almost every emperor died due to violence. The roman empire also had a
problem with the distribution of land. Almost all the land was owned by a few very rich nobiles and equites. That's what started the whole trouble
with the populares and the optimates. In the last few centuries of the western roman empire there were large periods of chaos. Rome was not a perfect
empire.
They also tried to control way too much land. I think they should have used the technique they used in gallia narbonensis in the rest of the empire.
The richest and most powerful from the indigenous people of gallia narbonensis could get jobs in the roman administration and I believe there were
even senators from gallia narbonensis.
However, I disagree with your point about the religions of Rome. Rome was not religiously strict. They had no problem with other religions, like the
jews or sects like the Isis and Mithras culti, as long as they still payed their tribute to the Roman gods. The christians wouldn't do that and that,
in combination with the fact that the christians became a large group, got the christians into trouble. The roman attitude towards gods is different
from ours: do ut des, I do something so that you will do something.
It is my unproven opinion also that polytheistic religions are much more tolerant to other religions, because they can mix with and adapt to new
religions much more easier than monotheistic religions.
There was no religious censorship I know of, like in christianity, and there were quite a few secularizing voices. In Epicurus' works the gods don't
interfere with men at all. I believe it was Cicero that attacked the ancient art of predicting the future with the organs of animals, the flight of
birds and the stars.



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