To the Editor:

In his zeal to normalize the off-the-wall reactions of previously sane Republicans to the Trump investigations, Richard Lowry (“What if the F.B.I. Were Investigating a Democrat?,” Opinion guest essay, Aug. 28) misses not one but several points.

First, the only investigations of Democrats that he can point to were obviously either factually deficient (Hillary Clinton’s emails) or so clearly political (Bill Clinton’s affairs) that any normal, nonpartisan person would — and did — question their legitimacy.

Second, the fact that both of those investigations occurred under Democratic administrations only reinforces the idea that, while there are of course extremists on both sides of the political spectrum, Democrats holding political office have generally been responsible enough to follow facts wherever those facts lead. That is a far cry from today’s Republicans who ignore undeniable facts to preserve the cult of Trump.

And of course we know that once Republicans regain control of Congress — if they do — they will investigate anything they can. The endless Benghazi “investigations” have already proved that. But as Benghazi also proved, today’s Republicans need neither an excuse nor a sense of vengeance to persecute Democrats. It’s just what they do.

Aaron R. Cahn
New York

To the Editor:

Richard Lowry tries to convince us that Trump supporters’ anger at a legitimate F.B.I. investigation is to be expected. After all, he claims, wouldn’t Democrats be equally angry had “their guy” been similarly investigated?

Well, Mr. Lowry, no they would not be similarly inflamed had Donald Trump, say, been a Democrat. I know it’s difficult for you to believe, but Democrats generally do like the idea of democracy and respect election outcomes, as well as the rule of law. So did Republicans 50 years ago, when they helped escort Richard Nixon to the door of the Oval Office.

Mr. Lowry may have succumbed to the notion that “the other side” must think the same way he does. Certainly the G.O.P. generally believes that if it’s “our guy” then any behavior is OK. But projection can be dangerously misleading. Then again, self-awareness has not been a particularly strong suit of Republicans in the era of Donald Trump.

And won’t such investigations be repaid many times over when Republicans are in power? Yes, all of us should fear unwarranted retaliation when Republicans are in power. The House minority leader has already promised to do that. All the more reason to expose these guys for what they are.

Stephen Polit
Belmont, Mass.

Protecting Civilians

To the Editor:

Re “Pentagon Makes a Major Shift to Reduce Civilian Bloodshed” (front page, Aug. 26):

The army’s announced plan to better protect civilians during combat is welcome. Quite apart from the morality of safeguarding noncombatants, however, the strategy has pragmatic value.

Killing fuels a desire for lethal vengeance. My data on 1,085 military actions in New Guinea around the time of European contact indicate that about 61 percent were launched to avenge a prior killing. There is no reason to believe this figure is atypical as an indicator of humanity’s disposition to seek blood vengeance.

Suppressing the lethal toll on noncombatants has the potential to ease this blowback, moderate the hatred that drives lethal conflicts and curtail a common obstacle in peace negotiations.

Paul Roscoe
Göttingen, Germany
The writer is emeritus professor of anthropology at the University of Maine and a specialist in the anthropology of war.

Early Signs of Alzheimer’s

To the Editor:

Re “‘Worrying if Alzheimer’s Will Arrive” (Science Times, Aug. 16):

As a neuroscientist and geriatrician with 40 years of experience, I often hear children of Alzheimer’s patients worry about their own futures. They usually express the same fear one son did in this story: “It’s in the back of my mind that it’s already in the process for me.” This is a reasonable concern for anyone, not just those with a family history.

Alzheimer’s changes start in the brain decades before symptoms appear. The good news for those wondering “to know or not to know” is that there are already some ways to identify these early changes, and more are on the way.

A simple blood test can diagnose the presence of amyloid plaques in the brain, and another can tell us about the amount of tau tangles, two hallmarks of the disease, even before there are symptoms. We will soon have even more ways — blood tests and retinal scans to diagnose brain inflammation, genetic alterations, changes in brain metabolism and other underlying contributing causes of Alzheimer’s, as well as smartphone apps to detect early, subtle changes in speech and language patterns that can be an early signal of dementia.

We are well on our way to a better future for the next generation: better tools for early diagnosis and drugs in late-stage testing that will likely soon be available and can be combined to provide personalized care for people with Alzheimer’s.

Howard Fillit
New York
The writer is co-founder and chief science officer of the Alzheimer’s Drug Discovery Foundation.

Let’s Replace the Word ‘Retirement’ With ___

To the Editor:

As an 85-year-old, I couldn’t agree more with Rebecca S. Fahrlander (letters, Aug. 17) that it is time to find a new term to replace the stereotyping and “touch of ageism” implicit in “retirement.” I would vote for the term “re-engagement,” which has worked very well for me during the 20 years since I turned 65.

It is amazing what a difference it makes to wake up in the morning knowing that I will be re-engaged with life and the world, rather than slowly retreating from both. “Re-engagement” has worked for me. I recommend it.

Darrel Morrison
Madison, Wis.
The writer is a former professor of landscape architecture and the author of “Beauty of the Wild,” published last year.

To the Editor:

Out of the mouths of babes! When I retired from teaching at Indiana University in 1996, my then 4-year-old granddaughter announced that she was excited to be going to Grandma’s “recyclement” party. As soon as those words popped out of her mouth, I knew she had something there! “Recyclement” was the perfect replacement for that old-fashioned word “retirement.”

Like many “retirees,” I went on to a second career, cofounding and serving as artistic director of a theater company where I am still “recycled” today.

Audrey B. Heller
Bloomington, Ind.

To the Editor:

When I retired in 1993 from being in charge of worldwide art movements for the Metropolitan Museum of Art, I called it a “permanent sabbatical,” and have since written five books for well-known publishers.

John Buchanan
New York

To the Editor:

My solution has been to use the word “rewired.” For those of us who remain active, either in our professional fields or in new and innovative ways, the word “rewired” seems appropriate. We can continue to “rewire” our brains and learn new skills long after we “retire” from our old jobs.

Helen Ogden
Pacific Grove, Calif.