Last week, the Trump administration issued a new rule relating to sex discrimination in health care. The rule affirmed that the word “sex” in civil rights law means biological sex and that this means health care providers cannot discriminate on the basis of a patient being biologically male or female.

This, of course, was a very sensible decision — one which would have been unremarkable as recently as a decade ago. Even today, chances are if you asked the average person on the street, they would likely agree with the idea behind the rule.

But times are changing. Among the progressives who run our nation’s elite institutions, a new, radical idea has taken hold: that the realities of man and woman are not based on biology but rather on what people feel they are, a concept which has been dubbed “gender identity.” And now, the left is working to embed this idea in every corner of American society, including our health care system.

This was why, in 2016, the Obama administration attempted by fiat to effectively replace “sex” in civil rights law with “gender identity.” At the time, Obama’s decision drew widespread praise from elites for supposedly protecting transgender patients. If it had not been blocked by the courts, it also would have turned health care as we know it upside down.

The problem is obvious: “gender identity” has no basis in physical reality. It is impossible for a doctor to tell from simply examining a patient what his or her (or hir or zir) “gender identity” is. A person’s “gender identity” is totally subjective and has no connection to one’s physical body.

However, health care is very much connected to the physical body. Whether one is biologically male or female makes a great deal of difference in how one ought to be treated — from finding the right medicine dosages to judging the risks of getting certain diseases. To place “gender identity” above biological sex would be to ask medical professionals to ignore their education and their training and instead operate solely on what a patient believes to be true — a dangerous idea if there ever was one.

But that is exactly what the Obama rule would have mandated that medical professionals do. It would have forced doctors, for example, to treat a biological male as a woman if that male believed he was a woman, no matter what adverse medical consequences might result. To do otherwise, according to our progressive elites, would be discriminatory.

Even worse, the Obama rule would have also coerced doctors into facilitating “gender transition” procedures such as cross-sex hormones and sex-change surgeries for any patient who wanted them, including children. Never mind that studies have shown the benefits of such treatments are mixed at best and that the health risks are significant. To decline to perform them would have run afoul of the law and put a medical professional’s career at risk.

There is only one word to describe this policy: insanity. For centuries, physicians have been obligated to act according to the Hippocratic Oath — to “first do no harm.” But inserting “gender identity” into health care law would compel many doctors to make a terrible choice: violate their oath or leave the practice of medicine altogether. And it would prioritize the personal wishes of patients over what is actually better for their health, likely putting the lives of countless people at risk.

While President Trump and his administration have drawn the ire of progressive elites for rejecting the Obama rule, they were absolutely right to do so. The ideology of “gender identity” should have no place in the hard science of medicine, and for now at least, doctors will be able to focus on the latter without having to worry about the former.

Terry Schilling is the executive director at American Principles Project. Follow him on Twitter @Schilling1776.