Pardon my French (and Latin)
In math, "equality" (A=B) and "diversity" (A≠B) are contradictory and mutually exclusive hypotheses. Mathematicians (except those working on Schrodinger's Cat) generally do not try to hold contradictory hypotheses as both true. However, in modern political and social theory it is necessary to value both "equality" and "diversity" at the same time, especially for those on the left who admire the French Revolution more than the American one. The French said "equality!” in French, while the Americans said "from diversity, unity!” in Latin.
There is good historical reason for that. The French in France were all French, so it was easy for them to say about themselves "equality!”. They didn't have to think about how the Germans, the Italians, the Africans, the Native Americans, and other people groups fit in until later, when Revolutionary France became Imperial France under Napoleon, and it turned out that the other people groups needed to be dealt with by conquest and by Superior French Power, rather than by “equality”. Whereas, in 1776 the North American population was a diverse mix of Germans, Italians, Brits, Scots, Irish, Native Americans, Africans, and many others, so the American Revolution necessarily had to involve not a flat-out “equality” statement like The French used. Instead the American founders chose to start with a diversity statement and then qualify it with a unity statement. We Americans attempted to acknowledge both the diversity (i.e. German ≠ Italian) and the equality (i.e. German-American = Italian-American) at the same time, without contradiction. Meanwhile, as a token hat-tip to “equality”, Jefferson slipped the words “all men are created equal” into his Declaration, but it was probably a bit uncomfortable for him, as a slave-owner, to do so. The Latin phrase used to describe the whole project was: "e pluribus unum". In English, the new and uniquely American culture which emerged was called "the melting pot". In that phrase, the intention of the "melting" metaphor was to evoke an image of ingredients previously diverse losing some of their heterogeneity by being melted down and becoming part of a new and homogenous alloy.
Now (in the 21st century) any loss of diversity, including what occurs in the ”melting pot”, is viewed with suspicion, and a popular new phrase is "the salad bowl", in which people groups supposedly retain their diversity while being tossed together. Or maybe, a rainbow. I am uncomfortable with that impulse for a number of reasons, including 1) It stinks of colonialism, in which immigrants to a new country of residence do not embrace local culture or learn the local language, but instead insist on establishing isolated colonies of their own imported culture and language, which need to be preserved, protected, and defended like an island in a sea of "foreign" culture. The better alternative is "assimilation", which is like the "melting pot", and necessarily involves some giving up of "diversity". And 2) I really don't like the end results of salad bowl attempts, which historically have often included civil war, and sometimes genocide.
One of my most important take-aways (so far) from Mahmood Mamdani's book "When Victims Become Killers" is this insight: that when European colonialists, first German then Belgian, arrived in Rwanda they found Hutu farmers, Tutsi cattle-herders, and Twa hunter-gatherers, living with tensions between them but still sustaining a centurie