These days our mongrel culture is at risk of being erased by an increasingly strident left, which is careering us toward a wan existence in which we are all forced to remain in the ethnic and racial lanes assigned to us by accident of our birth. Hoop earrings are verboten, as are certain kinds of button-down shirts. Yoga is dangerous. So are burritos and eyeliner.

It’s no longer just the online hordes that will string you up for your unintentional sins, though the cost of that public shaming can be devastating. In Portland, Ore., activists recently created a list of “white-owned appropriative restaurants” for residents to boycott on the grounds that white people probably shouldn’t make banh mi or dosas. This summer, the University of Michigan posted a job for a “bias response team” employee to “enact cultural appropriation prevention initiatives.” I wonder if they’ll go after people for using algebra (thanks, Muslims).

If this insidiously exclusionary view of culture goes the distance, it will take us back to a separate-but-equal reality that this country has spent the past half-century clawing our way out of. You can already see the beginnings of it, with the advent of racially separate commencements at schools like Harvard. Participants argue that it’s an important way to affirm group solidarity, but it’s not hard to imagine a demand for segregated schools in the not-too-distant future.

Consider the simple act of eating a meal in an era of cultural purity. This weekend I had dinner in Bay Ridge, Brooklyn, cooked by a Palestinian who was raised in Israel where her brother served in Parliament. Yet her restaurant is billed as Lebanese. And she accents her traditional dishes with herbs that would never be found on a plate in the Levant. But if proponents of cultural purity had their way, I’d have spent the evening cordoned on the Upper West Side watching “Yentl” and eating gefilte fish.

It doesn’t help that at the very moment that white supremacists in this country are reviving Nazi-era ideas about the purity of blood, the left is treating culture as something just as immutable. Two can play at this dangerous game. Indeed, the left’s insistence on cultural partition makes nobody happier than Richard Spencer and his fellow travelers on the alt-right, who are expert at mimicking the left’s identity politics to give voice to their twisted ideas of national and racial segregation. Americans should think very carefully before engaging with a politics that bears an eerie similarity to the beliefs of the people that marched on Charlottesville, Va.

None of this means that all cultural appropriation should be cheered: Sometimes it’s just in plain old bad taste. (See under: ear gauges.) But so long as the impulse is one of homage and not derision, we should encourage borrowing. Culture should be shared, not hoarded.

When I will inevitably get called a racist for cheering cultural miscegenation, I might borrow a line from the director of Taylor Swift’s new video, who wrote: “I am down for cultural appropriation. That sounds hot. Appropriate me.” Feel free to steal it as well.