August 1966. After Charles Whitman killed his mother and wife with a knife, he lugged three rifles, three pistols and a shotgun to the top of a University of Texas tower. From there he systematically picked off 14 people and wounded 31 others.

Whitman himself expected to die that day. He knew something was wrong, and left a suicide note.

“I do not really understand myself these days. I am supposed to be an average reasonable and intelligent young man. However, lately (I cannot recall when it started) I have been a victim of many unusual and irrational thoughts. After my death I wish that an autopsy would be performed on me to see if there is any visible physical disorder.”

A calmly rational analysis of his irrational urges.

Whitman was trained in gun use, knew how to handle guns safely. No matter; a brain tumor was pressing on parts of his brain that regulate strong emotion.

Recently, police interviewed a young lady who was sleeping in her car. She was “calm and cooperative,” had a plausible rationale for being there, and offered no hint of what was to come. Eleven hours later, after a last practice session at a gun range, she used a handgun to shoot up a YouTube campus before killing herself.

Were these people “mentally ill?”

In Stalinist Soviet Russia, people who criticized government policies weren’t always sent to the Gulag. Many were removed to “insane asylums” instead. Only a crazy person would deny the wisdom of the Party; the thing speaks for itself.

So — is the “unprovoked” act of shooting someone prima facie evidence of insanity? Are all murderous shooters crazy?

A common foil for Second Amendment worshipers is “mental illness.” Keep crazy people away from guns — gun problem solved. Better “mental health care” is what we need.

We should radically improve our capacity to provide mental health screening, diagnosis, and treatment. But will that dent gun violence? A dimple, maybe.

“Mental illness” is not one disease, but many, displaying a great spectrum of symptoms. Some are continuous life-long problems, at best kept under control; others are transient, or episodic.

Many of the mentally ill live isolated lives of numb desperation, friends and family unaware, or mystified. Most mentally ill people are no more likely to inflict violence than anyone else. (There are exceptions, like paranoid schizophrenia, in which delusions often focus on non-existent threats to the individual. Believing himself in danger, the paranoid might attack someone in “self-defense.”)

Most mass shooters are in all other respects sane and competent, but are driven to violence by an acquired worldview, or are raised from childhood in such a milieu. Powerlessness is a common theme — the world, the establishment, the boss, the government are unfair or oppressive, and we can’t do a damn thing about it. Except …

Nothing turns a 97-pound weakling into King Kong like a gun. Nothing evens the power balance like a bullet. Desperate, hopeless people can see violence as their only recourse; angry people are even willing to accept their own demise in return for the satisfaction of offing their oppressors.

Prevalence estimates suggest one in four Americans will experience some sort of mental illness during their lifetimes, while one in 10 is affected at any given point in time. Shall we ban a fourth of our citizens from gun ownership, just because at some point they have been diagnosed with “mental illness?” Is it safe to allow some categories of the mentally ill to own guns? Who gets to decide, and how?

Many who might qualify as mentally ill never come to the attention of authorities. Behavioral problems can be rationalized by family and friends as merely “odd.” Unless the ill person becomes violent, or threatens to injure himself, nobody can compel his mental evaluation. Sometimes the first time the system can detect or address his mental illness at all is when the victim becomes the perp, and winds up in jail.

Currently, access to effective psychiatric diagnosis and treatment is severely limited (unless you’re rich; when you’re rich, you can buy forgiveness and use “rehab” to enhance your celebrity.) Even when it’s actually available, treatment is very expensive, and insurance coverage is often limited or absent.

Even when a therapist suspects a potential for violence, confidentiality and due process apply. Clinical crystal balls are murky, and when a doc proactively contacts the court or law enforcement to notify of an “imminent danger to self and others,” the doc’s opinion must usually be reviewed and validated before the patient can be taken into protective custody. After that, what happens?

If he’s legally committed for treatment, he might wind up back on the streets until he stops his meds, and then the revolving door spins again.

Mr. Trump, we can’t blithely claim “the guy might be crazy, let’s take his guns until we know for sure.”

Mental health data don’t show that Americans have more mental health problems than do people in other countries with fewer shootings. Psych care in the United States, the number of psych professionals per capita, and the rates of severe mental disorders largely match those of other wealthy countries. A 2015 study estimated that only 4 percent of American gun deaths could be attributed exclusively to mental illness.

Psych treatment poses many challenges, but for overall gun violence, it’s another Band-Aid.

Jon Hauxwell, MD, is a retired family physician who grew up in Stockton and lives outside Hays.