On a current theory, transgender people have a gender that differs from their assigned sex. Traditionally, sex refers to one’s biological category, whereas gender refers to socially constructed norms that tell people how to behave. On this theory, binary people are exclusively male or female. Non-binary people are not so exclusive.

This theory asserts that some non-binary people are located on a gender continuum between pure male and pure female. On this theory, there are still other possibilities. Some people have two genders, some have no gender, and some change gender. Transgenderism is independent of sexual orientation in that transgender people can be heterosexual, homosexual, bisexual, or asexual.

On an even more fashionable theory, a transgender person’s sex (as opposed to gender) is assigned at birth rather than being a biological feature. On this theory, a person’s gender depends on identification. If a person identifies as a woman, she is a woman. If that same person identifies as a man, he is a man. On this fashionable theory, there is no objective standard for sex or gender. Such a theory holds that factors such as genes, body parts, reproductive function, and hormones do not make someone a man or woman.

Transgenderism has given rise to moral, medical, and legal issues. Writing in The Weekly Standard, Kevin Williamson points out that in sports, transgender individuals are dominating, winning events, and setting records in cycling, marathons, mixed martial arts, softball, track, volleyball, and weightlifting. In mixed martial arts, a transgender fighter seriously hurt her opponent.

In medicine there is an issue as to whether transgender people have a mental disorder. In psychiatry, gender dysphoria is a disorder that involves gender non-conformity that causes significant distress. Distress in transgender people is a serious matter given that a 2011 study by a UCLA think tank found that 41 percent of transgender people have attempted suicide.

In law, President Trump prohibited transgender people from serving in the U.S. military. This past month, the Supreme Court allowed the prohibition to go into effect while the lower courts consider it. In 2016, the Obama administration required schools receiving federal money to allow transgender individuals to use the bathroom matching their gender. The Trump administration eliminated this requirement.

The above transgender picture of the world is a conceptual mess. First, consider what gender is. Ryan Anderson, author of “When Harry Became Sally,” notes that if a person is a woman when she identifies as a woman, we still need to figure out what it means to identify as a woman.

If a person identifies as a woman when she sees herself as having a female gender, we’ve gotten nowhere in understanding what it means to identify as a woman. We still need to know what it is to see oneself as having a female gender. If, instead, identifying as a woman involves seeing oneself as biologically female, then gender depends on sex. On such an account, a transgender person might be wrong if she is mistaken about her biological sex. If gender depends on identifying with a set of features that society has arbitrarily said make someone a woman, then what makes someone a woman is arbitrary. This is implausible. The features are there for a reason.

If biological sex is not an objective fact but a status assigned at birth, as fashionable theorists now claim, this raises the issue of how and why society assigns a sex to a newborns. Again, it is implausible that this was done for no good reason and on an arbitrary basis. If, instead, people have an objective biology-based sex, then biology is not assigned at birth. Rather, it is recognized at birth if not earlier.

Second, there is the issue of whether a person is infallible with regard to her gender. To see this, consider whether an individual gets to choose what it takes to be a woman. If the individual chooses this, then absurd results occur. Being attracted to members of the same sex cannot make one person a woman and another a gay man. Yet if the individual gets to choose what sort of identification makes her a woman, such an odd result could occur.

Third, as University of Warwick philosophy Rebecca Reilly-Cooper points out, if there is a gender spectrum, then everyone is transgender. This is because no one is purely male or purely female in terms of having exclusively masculine or feminine thoughts, behaviors, and values. It is implausible, though, that everyone reading this column is transgender. Such a conclusion would horrify the muscled up gorillas at Darwin’s gym.

Even if there are people who have male and female body parts (consider intersex people) or unusual genetics, this doesn’t show that male and female are not biological categories. It doesn’t do so any more than the existence of cubs from a lion and tiger (for example, ligers) shows that lions and tigers are not objective biological categories.

Fourth, if the fashionable theory were true, human beings would be at odds with the rest of the animal kingdom. Reproductive function explains a lot about animals’ genes, bodies, and behaviors. This is also true for human beings. For example, the Y chromosome is inherited only from one’s father. Other material (ribosomes) are inherited only from one’s mother. The genetic, bodily, and behavioral differences of males and females across much of the animal kingdom are significant and not socially constructed. If animals have an objective biological sex, then human beings likely do so as well. After all, we’re just apes.

Perhaps as a way of respecting transgender people, we should allow for such a conceptual morass. We might want to allow for seemingly unfair athletic competitions, medical disorders that depend in part on whether the underlying condition causes suffering, and bathroom use depending on identification. We should be careful though. Incoherent metaphysical pictures of the world tend to slop over into other areas of thought.

Stephen Kershnar is a philosophy professor at the State University of New York at Fredonia. Send comments to editorial@observertoday.com