As California residents rang in 2018, they joined residents of Oregon and Washington, D.C., in having the option to revise their legal genders from either “male” or “female” to “nonbinary.” California’s enactment of the Gender Recognition Act, which was signed into law by Governor Jerry Brown last October and starts to take effect later this year, is but one more sign of a slow but steady sea-change. Washington State has followed suit, and similar third-gender options are under consideration in New York and Vermont. Under California’s new law, legal gender is dramatically reframed. No longer is it based on which sex (male/female) one was assigned as birth. Instead, legal gender will be based on what California lawmakers deem “fundamentally personal”: gender identity.

A person’s gender identification encompasses identification with certain physical features as well as gender expressions, gender norms, and gendered language. This means that, regardless of one’s physical characteristics, a Californian who does not identify as a man or a woman may change their legal gender to “nonbinary.” The motivation for this shift is clear: according to California Senator Scott Wiener, the nonbinary option means that “transgender and non-binary people will now be able to identify themselves as they are, not as who society tells them they should be.” (California’s law goes further than other states’ measures, permitting citizens to opt for nonbinary on their birth certificates, as well as other official documents like driving licenses.)

California legislators, and progressive lawmakers in other states, may be acting from the best of motives, but this swath of new legislation rests on a dangerous mistake. I say this as a nonbinary person, one who identifies as genderqueer and uses the gender-neutral pronouns they and them. I’m also a philosophy professor and spend much of my time thinking about the ways in which gender categories are constructed and enforced. For me, adding “nonbinary” to the list of legal gender options does not address the core problem: any legal system that requires a person to record their gender perpetuates government control over our bodies and identities.

Even as it was signed into law, the Gender Recognition Act was condemned by the right as opposing nature, science, and even God. Conservative groups argued that legal gender should reflect the supposed fact that nature designates everyone as a “biological male” or “biological female.” The California Family Council dubbed the Act the “Change Your Gender Bill” and derided it as replacing “a physical description of reality” with “a description of feelings and self-identification.” According to such groups, the government should uphold an ideology that determines gender on the basis of whether, at birth, you have a penis or a vagina. Many on the left, by contrast, have hailed the Act as championing trans rights and progressive ideals.

Despite their apparent disagreement, both conservatives and liberals share a fundamental assumption. Conservatives insist that the state should record what genitals I have. Liberals insist the state should instead record my self-identity. But both assume that the state should be concerned with my gender, whatever they understand that to be. In so doing, each side—whether tacitly or intentionally—endorses the use of legal gender to reinforce its own preferred gender ideology. To fail to see this appointment of the state as final arbiter is naïve and dangerous.

Senator Wiener’s comments in support of the Act also betray a widespread illusion that our gender identities exist independently of legal frameworks. He seems to believe that the state’s work is merely to reflect the genders of individuals. But the legal institutions we navigate every day do not simply reflect gender. Laws entrench the language, concepts, rights, and obligations constructing gender categories. The society that Senator Wiener believes “tells us who we should be” cannot be divorced from the institutions that structure that society: laws, as much as persons around us, set up the gender categories we do or do not identify with.

I grant to progressive lawmakers that it is better to have a third, nonbinary option than to limit constituents to “male” and “female.” It is an achievement to resist a near-universal legal practice of marking (and policing) bodies according to a binary classification of reproductive features. The best solution, though, would be eliminating all gender markers on state-issued identification. Americans should not have to resign themselves to a choice between two legally classified genders based on genitals and three legally classified self-identities.

The new law forces Californians to identify within a ternary range of options even though lawmakers apparently recognize that the scope of gender identities outside of male and female is vast and effectively unlimited. The Act states: “Nonbinary is an umbrella term for people with gender identities that fall somewhere outside of the traditional conceptions of strictly either female or male… such as agender, genderqueer, gender fluid, Two Spirit, bigender, pangender, gender nonconforming, or gender variant.” In other words, California now lumps all identities other than “male” and “female” under the “nonbinary” label. This reduces alternative gender identities to “not a woman or a man.” Far from escaping the gender binary, this and any similar law will continue to define every gender identity with reference to the binary. It perpetuates the common prejudice that binary identities are somehow more legitimate than the multitudes of other identities. Rather than deconstruct gender binarism, lawmakers have, in effect, shored it up.

Admittedly, the current legal system encodes gender so deeply that there is no immediate route to gender-neutral jurisprudence. The only viable options presently available to lawmakers might be three legal genders or two. But we must begin to think beyond this dichotomy. There is no good reason why our bodies or our gender identities should be recorded by the state. These designations have been used to police heterosexual marriage (until 2015), gender segregation in voting (until 1920), and females’ ineligibility to serve in the military (until 1948); they were also used to maintain females’ exclusion from universities (including my own, Yale, until 1969). History suggests that federal and state governments have encoded biological sex in the service of institutional sexism. Legal gender has, by and large, allowed the clean and easy exclusion of females from positions of social and political power.

I say “by and large” because these designations have also been used at times to correct sexism. Consider Title IX, the law that prohibits sex discrimination in education programs that receive federal funding. It is perhaps best known for requiring schools and universities to fund women’s sports, a measure that revolutionized women’s participation in athletics in the United States. Legal gender was part of enforcing Title IX: without the law’s ability to track male and female students, it might have been more difficult to ensure that females had equal access to education programs. Title IX is but one example of the ways in which legal gender has been used to secure certain rights for women in the United States.

But now Title IX faces problems. It was built on assumptions that did not take into account the complexity that intersex, trans, and nonbinary students introduce to education systems. The new landscape creates questions that Title IX is inadequate to answer: Can a school legally discriminate against nonbinary persons? Has a school sports league violated Title IX by forcing a transgender boy to wrestle against girls?

Perhaps these questions have clearer answers if legal sex is replaced by legal gender identity. But then, new worries arise. Consider, in this regard, California’s Gender Recognition Act. This Act unfortunately transgresses its own tenets by violating citizens’ rights to privacy. The legislation states in one breath that gender identity is “fundamentally personal” and that there ought to be “state-issued identification documents” that reflect gender identity.

Gender identities are complex and deeply individual. There is no single way to articulate the basis for gender identity, and not all citizens have stable and clearly defined identities. Any legal categorization of gender identity, which necessarily requires external criteria of identity (such as attesting to it “under pain of perjury”), is sure to be reductive and inadequate. I do not want one of my most personal understandings of myself recorded and fixed on my driver’s license any more than I would like my genitalia recorded on it.

I applaud California lawmakers for identifying and seeking to correct the negative impact that legal gender markers have on trans and nonbinary lives. But their solution takes us sideways, and other lawmakers would do well to carefully consider the costs. California’s solution fails to address the fundamental problem with any legal gender system: there is no defensible basis for legally recording people’s gender identity or sex, and we should not perpetuate the state’s assumed right to define citizens’ gender identities. The way forward is the way out.