Ok so as a genderqueer person, I hate this sentiment. Modern identities did not exist in the past and are NOT a basic, natural part of human experience and history. I really think that identity politics and the focus on the essence/identity has been harmful to the discourse. People in the past weren't nonbinary because that identity didn't exist, just like there weren't homosexuals. Actions are separate from identities, and people certainly have been having same-sex relationships and have been breaking gender norms. We might say that these behaviors are evidence for the existence of the will to live outside the binary norms of society, but we cannot say that these people are gay/bi/trans or whatever. In the same way, we shouldn't try to claim that third gender categories and such are binary trans people, since those didn't exist in the context of that society.
To be clear: I am not saying anything remotely to the effect of "people in history were actually, specifically, nonbinary, because nonbinary is an objective Thing that people can be separate from our modern Western sociocultural context." At the same time, I think its unhelpful to act as though, because we cannot act like our socially constructed identities are objective, it means we aren't allowed to ever use our words to relate to people throughout history.
I think @rq1nzorr said it best in this reply:
the historically common "i dont really have a sense of gender" that genderqueer-esque folks have said over the years is neither necessarily a feminist nOR binary trans statement on its own and i dont think we think about that enough at all. focusing more on the queer side of things im afraid we need to understand queerness as the social phenomenon it is and start discussing our history as "this is very similar or relatable to the [x type of contemporary queer] experience" rather than "this guy secretly was literally Biologically [x type of contemporary queer] in the year 1500" to even begin contending with historical enby genders
There are people throughout history who had experiences that were/are similar to experiences people who identify as nonbinary have today. That doesn't mean they Were Nonbinary (tm) (cr), because to get real abstract about it, no one Is Nonbinary (tm) (cr). People have experiences and some people use the concept of "nonbinary" to make sense of their experiences and connect to others with generally similar experiences.
Cisgender, binary women and men get to freely relate to any random person throughout history they want on a gender level. There is no "well the experience of being a woman/man in this culture was radically different from your own, so you should be really careful about claiming them for women's/men's history since that concept is heavily defined by modern Western constructs of gender!" despite the fact that the Victorian era, the Cult of True Womanhood, the Industrial Revolution, the construction of race and white supremacy, etc. radically changed how "womanhood" was conceived and what being a woman meant. Hell, even leaving gender: there are a million books for kids that talk about history and encourage them to relate to children and adolescents in different time periods throughout history. No one is concerned about the fact that "childhood" is also heavily constructed and what it means to be a "child," and even more a "teenager," has changed radically over time and place.
This is getting more outside of the realm of gender, but like. Did y'all know that no one during the period we call "the Enlightenment" used that term? It was the Victorians who retroactively delineated the eras of "the Dark Ages" and "the Enlightenment," turning a general intellectual movement that happened across Europe (& was also greatly influenced by interactions with the political & social philosophy of Indigenous Americans) into a Thing that did not exist during the era we are actually talking about when we talk about the Enlightenment.
Yet, I do still think there is some use in talking about "the [European] Enlightenment" as a Thing. It's helpful for us to be able to look back at history and make connections that were not obvious or could not have been made by people living at that time. I just think we need to be self-aware and responsible that we aren't "discovering" something objective, we are making a subjective choice to engage with and interpret objective information in a certain way for certain purposes.
I have the same approach to queer / trans history. Was the Public Universal Friend nonbinary? Well, on one level, no: not only did they not even have the term, their gender also cannot be understood outside of the very specific context of being born into a 18th century Quaker family in colonial America, and it cannot be divorced from how profoundly religiously rooted their rejection of gender was, how it was born from what was likely a near-death experience. We cannot know what was going on in their mind at all when it comes to what they "really" thought about their gender and their soul. Hell, technically, should I even be using "they/them" to refer to PUF? Historically, his followers used he/him to refer to him, since masculine pronouns were also used as gender-neutral pronouns when needed.
But on the other hand: we are actively making up what "nonbinary," means, and we are constructing nonbinary history, and there are good reasons to consider PUF as part of that history instead of starting it only when "nonbinary" started being used in the modern gender identity sense. They rejected binary gender identity, dressed androgynously to reflect this, changed their name, and rejected their old identity as a mortal woman. They understood this shift in gender through explicitly religious terms, yes, but many nonbinary people today also view their gender through explicitly religious/spiritual terms. "Nonbinary" is already an umbrella term that covers a range of experiences, and is meant to be used both as a term for individual identification and to describe a community of shared experiences and issues who are affected by things like exorsexism (and PUF was certainly affected by exorsexism, given how their rejection of binary gender made people at the time very uncomfortable). It is not that PUF Was Nonbinary in a strong, definitive sense, but rather that it is useful and meaningful for us in this present moment to see PUF as part of a lineage of experiences that people today express through the construction of "nonbinary."
Nonbinary people were only able to organize and define ourselves on the level we currently do recently. I don't think it helps anyone to try to retroactively assert that nonbinary identity is some timeless socially-unbound objective trait that has always existed. But what has always existed is people who, for a variety of reasons, do not see themselves as solely and entirely a woman or solely and entirely a man, who experience feeling outside of or beyond that strict divide, who were sometimes culturally supported in that and sometimes culturally suppressed. There are times where I think it makes sense and is even helpful to consider certain people as part of "nonbinary history" and refer to them casually as "nonbinary," & I think we can even do that without deluding ourselves into thinking that's an objective statement and not an active subjective choice on our part.
After all, it is true that people throughout history did not have the concept of "homosexual" or "gay" as an identity in the way people do right now (again, particularly in the West). But people have been having what we would consider "gay sex" for ever, and people have been expressing what we would consider "transness" for ever, and there are real benefits to pointing out that history and CHOOSING to connect those historical experiences to our modern experiences.
And there are times / cases where I think that wouldn't be helpful, and many cases were various different interpretations can be helpful, and we don't have to choose just one to be The Truth! There are areas of life where we simply cannot avoid that we are just making shit up, and I am a strong believer that we should navigate social construction by making shit up consciously, self-reflectively, and with a sense of responsibility. I think we can create a sense of harmony and unity between "people throughout history have had radically different perspectives and experiences than us, and we cannot just project our current thoughts and social constructs back onto them and assume its accurate" AND "people have, in many ways, not fundamentally changed over the history of the human race, and it is good to feel connected to the past and realize that history is full of experience we can relate to and even learn from."
