Anti-Trans Activists (ATAs - a.k.a. TERFs) often demand a definition of “woman” that excludes trans women, framing it as a simple question with an obvious biological answer. Common variations include:
The underlying rationale is that there must be a definition that includes all cis women while excluding trans women (and cis men). This is, of course, virtually impossible to do. Nonetheless, Anti-Trans Activists will generally insist this definition must:
However, as philosopher Talia Mae Bettcher argues, the “what is a woman” question functions rhetorically to put the burden on trans women to prove their womanhood according to dominant standards that marginalize them from the start. It assumes a single, fixed meaning of “woman” and demands trans women argue for inclusion in a category defined to their disadvantage.2
Meanwhile, we do not subject cis women to this level of invasive scrutiny or demand they “prove” their womanhood. Cis women's gender identities are taken as valid by default - it is only trans women who are forced to jump through hoops simply to have their self-identification recognized and respected.3
Julia Serano notes that both the medicalized “wrong body”4 model and the “beyond the binary”5 transgender model still presuppose the dominant meanings of gender categories. They position trans women as marginal cases that must justify their inclusion, rather than taking their womanhood as presumptively valid.6
Instead, Serano advocates for expanding our understanding of womanhood to include trans women from the start, not as an afterthought or special case. She calls for recognizing the diversity of women's bodies and experiences, with trans and cis women's womanhood seen as equally valid.
The most consistent and humane definition is: A woman is anyone who sincerely identifies as a woman.
This centers the fact that gender identity determines who is a woman, not anatomy, chromosomes, or conformity to stereotypes.
As JoJoFromJerz powerfully asserts, “A woman is whatever the hell she wants to be. We get to decide.”7
Biological essentialism fails to capture the diversity of both cis and trans women:
We don't actually use genital checks or DNA tests to determine if someone is a woman in any real social context. Gender is complex and multifaceted, shaped by social and cultural forces beyond biology.
A critical point often obscured in this debate: woman/man are not the same as female/male.
This distinction is philosophically crucial because it allows us to understand that:
When someone argues “trans women are not female,” they may be making a different categorical claim than “trans women are not women.” These require different answers, and conflating them is philosophically imprecise. The important point: trans women are women, period.
A strong definition is one that:
Our definition meets these criteria:
The definition is inclusive of all women and exclusive of all men. When critiquing any proposed definition of “woman,” the exceptions are not irrelevant edge cases - they are the test that validates or repudiates the definition.
In exploring how to define “woman” rigorously, some folks propose alternative frameworks that, while phrased differently, arrive at remarkably similar conclusions.
One such approach leverages Serano's concept of “subconscious sex” - defined as “an unconscious and inexplicable self-understanding regarding what sex one belongs to or should be.” Using this concept, some propose the definition: “A woman is an adult human whose subconscious sex is female.”
This approach uses a thought experiment as a diagnostic tool: if you woke in a body of a different sex with a button to change back permanently, would you press it? Your honest answer supposedly reveals your subconscious sex, and therefore whether you are a woman.
But let's trace this to its logical endpoint. What is this thought experiment actually measuring? When you answer “no, I wouldn't press the button,” what are you doing? You are identifying at the deepest level with being a particular sex. You are expressing a fundamental, genuine self-understanding about your gender.
In other words: subconscious sex ultimately reduces to sincere, fundamental self-identification - it's self-identification at an unconscious, deep level rather than surface-level conscious declaration.
So the definition “A woman is an adult human whose subconscious sex is female” ultimately reduces to: “A woman is someone whose deep, fundamental self-identification is female,” which is functionally identical to: “A woman is anyone who sincerely identifies as a woman.”
Both approaches:
Different framings can capture the same truth. The philosophical work matters more than the specific language used. What unites these approaches is the recognition that gender identity is fundamental to gender.
One might ask: doesn't this definition create problems for non-binary and gender-fluid people?
The answer is no - it actually handles them elegantly:
Questioning and exploring people may not yet have settled on a sincere identification. That is part of self-discovery, and it is valid. Communities of non-binary and gender-fluid people are particularly equipped to welcome those in flux, offering space for exploration without premature categorization.
The point is not to police or validate anyone's self-discovery process, but to respect it.
TERF arguments rely on several logical fallacies:
When confronted with the reality of biological diversity, TERFs often deflect by dismissing intersex people as irrelevant exceptions. But as biologist Dr. Anne Fausto-Sterling notes, “Biologically speaking, there are many gradations running from female to male.”8
The popular counter-point to this is typically some variation on “we do not make exceptions the norm.” Except we do, all the time, and when we want to make a definition, the exceptions absolutely do matter and count as everything. It is the test that validates, or repudiates, the proposed definition. Though my attempt is not original, it does pass its own test/validation. That is to say, this definition is inclusive of all women, and exclusive of all men. This is the core golden nugget that we really need to recognize, identify, and understand. This is what makes a strong definition.
I posit that it is the only definition that is both strong and passes its own test/validation. And now that I said that, I am sure there will be someone who will comment with another different strong definition that passes the above test.
Trans identities have existed throughout history and across cultures, from Indigenous North Americans to Indian Hijra to Polynesian Mahu.910 In trans subcultures, self-identification is centered11. Terms like “woman” are expanded to paradigmatically include trans women, without qualification. An expansive theory of gender must recognize this multiplicity of meanings, not insist on a singular definition that erases trans perspectives.
Some will object to our definition, calling it circular. But this objection fundamentally misunderstands what circularity means in definitions versus arguments.
Arguments should not be circular. A circular argument - one that assumes its conclusion as a premise - is a logical fallacy. “Women are women because women are women” would be circular reasoning.
Definitions, however, can and often are circular. Most important concepts resist non-circular definitions. Consider:
Love: How would you define love without reference to how love feels, or what love causes us to do? Any definition of love circles back on itself.
Consciousness: Try defining consciousness without some reference to the quality of being conscious.
Justice: What definition of justice doesn't ultimately refer back to justice itself?
An oak tree: Defined as a tree grown from an acorn. What is an acorn? The seed of an oak tree. Circular, but perfectly valid and useful.
These are all circular in phrasing, yet they are strong definitions because they have qualifiers and pass their own tests. The circularity is not a flaw - it is characteristic of how participatory and fundamental categories work.
Our definition - “A woman is anyone who sincerely identifies as a woman” - has a crucial qualifier: sincere identification. This is not performative identification, not surface-level declaration, but genuine self-understanding. The qualifier prevents the definition from collapsing into meaninglessness.
Moreover, the definition works because:
The reason getting hung up on circularity is a distraction: the real philosophical work is in the qualifier. The sincere identification criterion is what makes this definition rigorous, robust, and universally applicable. Whether or not it “sounds circular” is irrelevant.
We need a definition of “woman” that treats all women with dignity, reflects how gender identity functions in the real world, and centers individuals' self-understanding. Self-identification does that better than the alternatives, circular or not. Definitions can be circular. Arguments should not be. Anti-Trans people may pose the question or demand as though they are seeking a definition, but they are making an argument.
So while it may have a circular element in its phrasing, it does not meet the criteria of a circular argument fallacy. The criterion is the important bit, and as such, the definition is not simply assuming the truth of the conclusion as a premise. If you dive into definitions a bit more deeply, you will find most all definitions are circular in some way.
That is why getting hung up on circularity is a distraction from what matters: fighting for all women's rights, well-being and liberation. Trans women are women, period, regardless of how neat and tidy our definition is. It's time we recognize that and move forward together.
Constantly interrogating trans women's identities fuels a climate of prejudice and hostility:
Fixating on defining womanhood in relation to a tiny minority is a cruel distraction from the sexism all women face, especially from cis men. As JoJoFromJerz notes:
“They don't want us talking about Amber Thurman or Kate Cox or Amanda Zurawski… They want us tying ourselves into knots of our own making by taking the bro bullshit bait of their distractionpalooza agenda.” 12
These are women who were denied life-saving abortion care, left to suffer and nearly die because of how womanhood has been gatekept. Obsessing over “what is a woman” does nothing to materially improve women's conditions.
This is why the best answer to this question/tactic is simply to not engage with it on their terms. Respond with a very pithy quote from JoJo: “If you're asking it means you don't know and you don't care to know.”
If you must engage with this question/tactic, turn it around and ask them to provide it. Then proceed to point out every possible exception to their definition. I feel I must give you the disclaimer that such an effort will be as time consuming as it will be emotionally exhausting, and it is highly unlikely you will change any hearts or minds that engage with you. You will leave breadcrumbs for the readers who come after, and this is something I feel is very valuable; however, this should not come at the cost of your emotional well-being.
Womanhood is a vast and varied category. Trans women are women, period, regardless of their bodies or presentation. “Woman” describes an inner identity and sincere gender identification, not a rigid biological classification or conformity to stereotypes.
Our focus must be on fighting the real threats to women's rights and safety. We must stand in solidarity with the most marginalized women, including trans women, and work to dismantle patriarchal oppression in all its forms. Anything less is not feminism. Anything less is gatekeeping womanhood, and at that point you are being part of the problem, not standing up as part of the solution.13
True allyship means respecting trans people's self-understanding, not imposing exclusionary definitions on them. It's time to stop asking “what is a woman?” and start asking “how can we make the world safer for all women?”
That is the only question that matters.