We know we're progressing up the diversity scale when violence between immigrants and locals expands to incorporate trouble within the immigrant ethnic groups themselves. That shows that a critical mass of diversity has been reached.
And we must always celebrate diversity.
Given that Shia and Sunni Muslims the world over have been at each others' throats, often with murderous intensity, for god knows how long, I've been keeping an eye out for the same happening in the Emerald Isle.
And sure enough, confirmation came this week. This confirmation took the form of the following headline in the Irish Times: "Imams deny rift between Shias and Sunnis in Ireland".
As the man said, never accept something as the truth until it's been officially denied. We can now look forward to this enhanced manifestation of cultural diversity enlivening our lives over the coming years.