The Roman Empire as a synthesis

[Connacht]

I wanted to start with this interesting quote (from the Italian journalist Indro Montanelli) about the role of Rome as a synthesis of civilizations:

If we see things from above and give them a reason, we could say that Rome was born with a mission, that she accomplished it and with it ended.
That mission was to recollect the civilizations that came before her, the Greek one, the Eastern one, the Egyptian, Carthaginian, Celtic ones, to merge them and spread them in Europe and in the Mediterranean Basin.
Rome didn't invent so much in philosophy, art or science, but gave them roads for their circulation, armies for defending them, a formidable and complex system of law to guarantee their developement in order, and a language for making them universal.
Rome didn't invent even political forms: monarchy and republic, aristocracy and democracy, liberalism and dispotism, were already tested before. But she made them models, and in every one of them was brilliant for practical and organizative genius.

Abdicating with Constantine, Rome left her administrative structure to Constantinople, who survived for other 1000 years. And even the Christianity, in order to triumph in the world, had to became Roman. Saint Peter well understood that only by travelling in the Via Appia, Cassia, Aurelia and all the other highways built by Roman engineers, not the labile paths travelling the desert, the disciples of Jesus would have spred in the Earth.
His successors would have been called Pontefices Maximi just like those who managed religious questions in the pagan Urbs. And against the austerity of the Jewish rule, they introduced in the new liturgy many elements of the pagan one: the pomp and spectacularity of some ceremonies, Latin language, even a little vein of polytheism in the veneration of saints.
So, no more as the political centre of an empire, but as the mastermind of Christianity, Rome became again Caput Mundi, and remained so until the Protestant reformation.

And thus start a discussion about what was the practical legacy of Rome in her recollecting and mixing various different cultures and civilizations, before forging a new collective ideal which then became the basis for the modern European nations.