The claim that President Donald Trump is mentally unwell has a particular valence in today's charged political environment. It isn't supposed to sound like a partisan criticism. It's supposed to sound like an objective statement of medical fact.
That's especially true when it's uttered by mental-health professionals, as in the recent collection of essays The Dangerous Case of Donald Trump: 27 Psychiatrists and Mental Health Experts Assess a President. But it's also true when the allegations come from civil society, as in the pro-impeachment ad paid for by billionaire Tom Steyer, which calls Trump "mentally unstable."
And it's even true when the assessment comes from politicians like Sen. Chris Murphy, D-Conn., who used the "unstable" line in recent hearings on the president's power to wage nuclear war.
Enough. Stop using the language of mental health to criticize the president for his actions, his policies and his character. Calling the president crazy is a way of trying to end political conversation, not start it. It fundamentally contradicts the goal of politics in a republic, which is supposed to be based on dialogue and engagement, not conclusory diagnosis.
The psychiatrists have the most to answer for. They haven't examined Trump. They haven't subjected him to the protocols of personality instruments and assessments that would go into an ordinary diagnosis. Rather, they are leveraging their professional knowledge and status to "assess" his mental health for purposes of political criticism.
What's more, the contributors to the Dangerous Case volume acknowledge as much. As part of their efforts, they needed to explain why they reject the so-called Goldwater Rule, which tells psychiatrists that they cannot comment on the mental health of public figures they have not examined.
Their proffered answer is, more or less, that the threat to the country from Trump's presidency is so great that it outweighs countervailing ethical principles. That is, political imperative justifies the departure from prevailing medical ethics.
The intended effect of the psychiatrists' and psychologists' claims is surely to weaken the president's political position by encouraging the public to treat him not as an ordinary politician with mistaken or repulsive views but as someone who is dangerously ill. Their point is that Trump's actions are not those of a controlled, balanced person who can be reasoned with.
From this it follows that critics shouldn't think of the president as a standard political opponent, a worthy interlocutor for civic discourse, but as an object of treatment. The professionals are all committed to the view that there should be no stigma attached to mental illness, but their claims nevertheless raise the possibility that the unwashed public might look down on or pity Trump for his purported illness.
The idea that one's political opponent can be "cured" by "treatment" runs counter to the democratic idea that citizens can shape one another's political judgments by rational discussion. Mental illness can't be cured by logic or reason, at least not according to most mental-health professionals.
You might try to reason with a mentally unwell person. But you wouldn't expect that reasoning process to be sufficient or even very successful, because the person with the disorder is, by hypothesis, suffering from "a mind diseas'd," as Shakespeare put it in Macbeth. And mentally instability is not a ground for impeachment under the Constitution, notwithstanding Steyer's ad. It's not a high crime or misdemeanor.
The Constitution does provide for temporary presidential removal by the vice president and a majority of the Cabinet if the president is unable to fulfill the duties of his office.
But the 25th Amendment makes no specific mention of mental illness. And President Trump is plainly able to fulfill his duties, even if not in the way that liberals would consider proper.
The upshot is that the politicians' charge that Trump is unstable reflects the judgment of the others who use similar terminology. What they really mean is that they don't trust his judgment, and that he might do something rash and potentially harmful.
Yet perfectly sane, mentally healthy people commit rash or mistaken actions all the time. They get angry and say foolish things. Not every bad act is the product of mental disease.
It's not too late to walk this back. Blame Trump for his actions, his policies or even his character. But don't presume to judge his mental health -- lest ye be judged in return.
NOAH FELDMAN is a Bloomberg View columnist. He is a professor of constitutional and international law at Harvard University.