There are two competing claims in the debate on transgender issues. The first is the historical norm of Western culture: one’s gender should be considered the same as one’s objective biological sex. The second is the core assertion of the transgender movement: a person’s gender should be viewed by others and by the law as a matter of subjective identity. Both claims are defensible, but both cannot be right. I will refer to these two views as the objective and subjective views even though I admit these terms are problematic. My conclusion (spoiler alert) is that both views should be respected, since (among other reasons) there is no possibility of any public proof that either is right or wrong.

The clearest thinkers on both sides of the debate acknowledge a valid distinction between (1) the mere fact of biological differences between males and females and (2) the things that culture and psychology do with the concepts of “male” and “female.” This culturally and psychologically generated construct has come to be distinguished from biological sex and called “gender,” though the terms are still often used synonymously. Acknowledging this theoretical distinction, the practical issue of what to do about the possibility that an individual’s gender identity may differ from the individual’s biological sex remains entirely unresolved.

There are a host of valid questions to ask in resolving this issue: how do the different possible approaches affect society? How do they affect the individuals most concerned? Which approach most goes with the grain of the critical realities that society and the individual will be bumping up against going forward? What causes account for the disjunctions between individuals’ gender identity and their biological sex? How has our culture traditionally handled the issue and for what reasons? How have other cultures handled the issue and for what reasons? What do the highest authorities that one accepts have to say on the matter?

Let us now focus on one of the many questions that arises as soon as transitioning genders is contemplated as a possible response: is it actually possible to transition genders? Certainly this question implicates the competing claims that we started with (the objective vs. the subjective view): one’s philosophy of gender will affect one’s answer. But let us proceed by temporarily joining the unreflective scientist in pretending to be merely empirical.

While wearing our empirical hats we cannot access gender in the cultural/psychological sense other than through surveys and interviews and other “soft science” methods that rely fundamentally on language rather than on direct observation. Let us be purists and for the moment eschew the contamination of language and culture and symbols to the extent possible in favor of that which can be methodically microscoped and MRI’d and measured in millimeters or milligrams. Indeed, with this approach, we cannot even directly observe biological sex. We may only observe discrete traits associated with biological sex by habit arising from statistical correlation. Following are among the major clues of biological sex:

• Presence of male/female genitalia
• Presence of other components of the male/female reproductive systems (uterus, prostate, ovaries/testes, etc.)
• Presence of male chest/female breasts
• Amount of body hair
• Ability to conceive/impregnate
• Hormone levels
• Skeletal structure/body shape
• Facial structure
• Brain structure (“There are well-defined differences [between males and females] in brain structure that result from fetal exposure to gonadal steroid hormones. These morphological differences, in concert with the effects of sex steroid hormones on neuronal function, are proposed to support diverse nonreproductive differences between males and females such as differences in pain threshold and cognitive style and the greater glucocorticoid response to stressors exhibited by females compared with males.”)
• Ability of body to spontaneously maintain male/female structures and processes
• Chromosome combination (XX or XY).

Let us ask how possible it is to transition from one sex to the other with respect to each of these traits. I’m afraid that is as far as empiricism can take us; we must to some extent transcend empiricism in order to then opine on the extent to which it is possible to transition sexes not just with respect to a discrete trait but overall. And we must entirely give up any pretension of empiricism in order to then opine on what this means, if anything, regarding whether it is possible to transition genders.

Please note: I am not an expert and the following chart may contain mistakes.

Sex-Influenced Trait Used To Identify Biological Sex	Is It Possible To Transition From One Sex To The Other With Respect To The Particular Trait?
Presence of male/female genitalia	Partially. Surgery can remove genitalia and then add structures similar to the genitalia of the other sex, but the added structures cannot function fully in all respects like natural genitalia. Therefore, a complete transition is not currently possible, but a partial one is.
Presence of other components of the male/female reproductive systems (uterus, prostate, ovaries/testes, etc.)	Partially. Any of these structures can be removed, although removal comes with significant medical consequences regarding, among other things, hormones. However, there is a very limited ability to successfully transplant these organs into a body that was born without such structures.
Presence of female breasts/male chest	Largely Possible. Hormone therapy and surgery should enable a biological male to obtain female-looking breasts that largely function as female breasts: even nursing is possible. The transition in the other direction is also possible, though in both cases structural differences may remain.
Amount of body hair	Largely Possible. Hormone therapy can increase or decrease body hair.
Ability to conceive/impregnate	Not Currently Possible.
Hormone levels	Largely Possible using hormone therapy.
Skeletal structure/body shape	Somewhat possible before puberty, largely impossible after puberty, although hormone therapy will affect skeletal structure even after puberty.
Facial structure	Partially/Largely Possible. Surgery can, within an acceptable risk threshold, change facial structure to an extent dependent on the individual even if hormone treatment is not started until after puberty.
Brain structure	Somewhat possible. Hormone therapy and other factors affect brain structure. More research is needed.
Ability of body to spontaneously maintain male/female structures and processes	Largely impossible. Hormone therapy must be continued or many of the alterations caused by hormone therapy will disappear. In significant measure, a body will continue to act in accordance with its biologically sex to the extent it can.
Chromosome combination (XX or XY).	Not Possible. (As far as we know.)

A complete and accurate version of this chart would be the utmost extent to which science could take us. We would then have to turn to some other authority (reason, intuition, ethics, religion, philosophy, history, etc.) to lead us to any further conclusions, such as how often (if ever) sex change is a good idea, whether it should be permitted for pre-pubescent minors, etc. To the extent that there is an emerging consensus among social workers or psychologists, such consensus is inherently suspect if it ever claims for itself the sanction of hard science. It is also inherently suspect to the extent that it represents the consensus of a group of people who overwhelmingly hold particular ideological and political orientations the correctness of which is not subject to proof.

The next question I will address is whether, on the whole, it is possible to transition one’s sex. I rely on reason and intuition, viewing the foregoing data as a whole, to conclude that it is possible to cause one’s body to appear and function somewhat like the opposite sex, but a complete transition is impossible and will remain so for the foreseeable future.

Now for the real question: what does this say, if anything, about whether it is possible to transition one’s gender, defined as the social and psychological construct?

Some would argue that this says nothing at all about gender: one can be a non-transitioned biological male whose body is unambiguously male but who identifies as female. Gender is entirely subjective, and biology is completely irrelevant to the question. Identity is all. Sex is of the body; gender is of the mind; and never the twain shall meet.

And this position would be viable if the mind and body were separable; but they are not. One of the things that proves this is that biological males and females who identify as the opposite gender often (usually? almost always?) want to look and sound more like the opposite gender and/or be called by names or pronouns belonging to the opposite gender. Their own typical dissatisfaction with the disjunction between body and identity rebuts the “biology is completely irrelevant” theory of gender.

And this dissatisfaction is understandable and perhaps inevitable. Our consciousness of gender arises in large part if not entirely from biological sex even though it is distinguishable from biological sex. The two remain always closely tied together. If gender is what society and psychology do with biological sex, then biological sex remains always the thing that is being manipulated by society and psychology to create gender. The two are so closely intertwined, indeed, that most people historically and perhaps still now have been content for the most part to have the two concepts fused for all practical purposes except in their most reflective moments.

In light of the interconnection of sex and gender, what does the impossibility of anything approaching a complete transition of sex say about the possibility of transitioning genders? I must tread lightly here, because I am not an expert and lack the experience that would qualify me to offer anything like a comprehensive answer to this question. But as a mere thinker, I think I can say at least this much: the impossibility of a complete sex change combined with the interconnectedness of sex and gender implies that a transgender individual is in an inherently difficult situation. The disjunction between biology and identity, as long as it persists, will be both painful and unyielding. And it has a tendency to persist throughout life, since biological sex and gender identity both seem to resist intervention.

Science cannot measure which is the more intractable. Even if it could it would have absolutely nothing to say about the ethics of either kind of intervention. Science is no more capable of answering such questions than a thermometer is of telling me whether a poem is any good. People, including me, have their opinions, and I foresee no likelihood of consensus.

It would seem that the “objective” theory and the “subjective” theory of gender both recognize the disjunction as a problem, or at least a potential problem. The proponents of biological sex as the defining factor have a natural tendency to want to fix the individual’s identity to match their biological sex, including as one possibility the alteration of the individual’s gender concepts to enable a re-identification with the gender that matches their biological sex. The proponents of gender identity are naturally more open to altering the body. Either the mind or the body must change, if possible, or the disjunction and resulting discomfort will continue. But no kind of solution has met with unmitigated success, to say the least.

Since both competing theories implicitly recognize the disjunction as a problem and neither side can provide a complete solution, one would think that it would be respectable, at the least, to suggest that society should do what it can to prevent the disjunction from arising in the first place. Nature provides individuals with a biological sex, and society should do what it can to help individuals identify as the matching gender, including by re-examining some of the ways it defines and deploys gender, thereby avoiding the painful and unyielding disjunction. People should not only be legally free but should feel unconstrained socially in acknowledging that the disjunction is undesirable, as all sides agree though with different reasoning, and in suggesting in a reasoned and respectful manner what seems to them the appropriate approach to the reality that some people experience it. It is simply invalid to brand particular opinions on this matter as hateful or discriminatory and subject them to “cancel culture.” Not only are no opinions on the matter inherently hateful, none of them are even provably right or wrong.

To recap: sex and gender are closely related but distinguishable. There seems to be a strong consensus from most if not all sides of the transgender debate that it is often painful when the two do not match and that steps should be taken to enable them to match. By definition, any such steps must involve an intervention to change either the (apparent) biological sex or the gender-related beliefs of the individual. Neither approach has proved entirely successful. Deciding which approach is preferable and what steps, if any, ought to be taken to avoid the disjunction in the first place will inevitably depend upon one’s position on various philosophical, ethical, religious, and historical issues, most of which are not subject to scientific examination but only to persuasive rhetoric–i.e., to competition within the marketplace of ideas. I certainly have my opinions, but the only thing I insist upon here is that this marketplace of ideas should remain free not only from government interference (a First Amendment issue) but also from the various forms of cultural compulsion that have lately been brought to bear. Indeed, to malign those who hold the opinion that it is desirable for biological sex and gender identity to align is itself a sort of bigotry, as much worth resisting as any actually hateful ideology.