Today I got a nasty TERF anon and I also really upset myself looking through replies on Twitter. The anon didn't make sense and doesn't deserve refuting, but I wanted to take a second to spell out something I see as missing in the discussions between transphobes and trans folks and their supporters:
When we say "trans women are women," transphobes blink and laugh. It strikes them as preposterous. They respond by saying "my dog is a cat" or "Freedom is slavery." Transphobes don't deserve our breath because they aren't listening, but for people who aren't actively filled with hate and dismissal of trans folks' feelings, I think this could use some explanation.
There are certain experiences that we think of as shared experiences of womanhood. But these experiences are never REQUISITES for being a woman; they're merely things that people who are women often experience. These things include biological experiences like menstruation, pregnancy, breastfeeding, childbirth, and cultural experiences like, say, getting catcalled, or getting a training bra, or being the only woman in a meeting in an office.
It's not problematic to discuss shared experiences that women often have. What's problematic is suggesting that they are necessary in order to be a woman, or to assume that only women experience them. This is patently obvious: not every woman (not every cis woman!) experiences pregnancy or menstruation or breastfeeding. No one would say you need to have been catcalled to call yourself a woman.
Moreover, we know that different groups of women have different experiences as sub-groups. Women of color experience things that white women never do. Fat women experience things thin women never do. And not just body things: women in high-powered careers experience different things than women who work in other ways. Women athletes have a shared experience that is not shared by non-athletes.
When we say "trans women are women," we mean just that. They are women. But we do not deny that they have had a different experience in life as trans women. The experience of growing up identified as a boy while knowing oneself to be a woman is surely something a cis woman or man cannot know. This doesn't conflict with being a woman because there are many, many ways to be a woman. Because women share lots of experiences, but none of us share them all.
This is why it's so important for feminists to fight for trans folks, beyond it simply being the right thing to do: because the same forces that tell trans women that they don't count as women are the forces that tell all women there's one way to be a woman. That being a woman means a specified list of things, your own desires be damned.
It's all a lie. There's no one way to be a woman. There's no universal experience of girlhood or womanhood. There is no single experience that ties us all together. But that doesn't mean we don't share something essential, but it's amorphous. It's constantly shifting and changing and never essentializing.
This is how I can share certain experiences of womanhood with fellow moms I know that I'll never share with other women. How I can share certain experiences of sexuality with queer friends that I can't with het friends. That I can understand how I share something meaningful with trans women even as our lives have looked very different.
This is why it's harmful to make assumptions based on people's sex/gender: because you can't assume shared experiences on the basis of shared gender. This is always true, even among cis women, and it causes major problems (see: all of white second wave feminism). And it's the same with our trans sisters.
I think if people could understand this, we'd be in a much better place.