The reform is being driven by Macron—the youngest president in French history, a childless man who married his former high-school drama teacher—whose campaign promise to extend fertility treatments to lesbians and single women is aimed at bringing France in line with some of its European neighbors, and bringing French law in line with reality. (It is also seen as a logical extension of France’s 2013 legalization of gay marriage. If gay people can marry, the logic goes, then they should be able to have kids.)

The debate has revealed many of the paradoxes of modern France, especially the inconsistencies in its notion of universalism versus particularism. The French republic is built on the idea of universal rights, and that groups, regardless of ethnicity or religion or sexual orientation, should not receive special treatment or status. (This is also why it is illegal here for the state even to acknowledge the race of individual citizens.)

But this has led to other contradictions: All families are equal, but some families in France—straight families—have been more equal than others when it comes to access to fertility treatments. Currently, if a married lesbian couple has a child using a sperm donor, the biological mother has full rights over her child, but to share those rights, her partner has to go through a lengthy process of formally adopting the child.

And then there is the question of how theory collides with reality. “Single-parent and gay-parent families already exist. That is a fact, and it would be hypocritical not to see them and to continue not to recognize them,” French Health Minister Agnès Buzyn said last month when she presented the bill to the National Assembly, where the speaker’s dais sits beneath a tapestry of Raphael’s The School of Athens, the famous fresco in the Vatican Museums. Buzyn insisted it was right that France’s legislators—and not, for instance, the free market—be the ones to set the terms of bioethics in France, and that lawmakers should weigh “the confrontation between the possible and the desirable.”

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Macron’s own La République en Marche party, an umbrella that includes progressives and Catholic socialists alike, is divided on the issue, and members are allowed to vote their own conscience, not the party line.

France is founded on principles of laïcité—secularism—but it has deep Catholic foundations. As with the law legalizing gay marriage, the one to broaden access to fertility treatments has stirred up a Catholic-inflected resistance movement. But the resistance doesn’t entirely fall along predictable right-left or progressive-conservative lines. It taps into historic debates about the French family as a pillar of the state and much deeper questions about national identity—essentially over who is able to bear French children and therefore transmit the ineffable essence that is Frenchness.