A fascinating story in the New York Times almost 20 years ago featured the headline “Nuns Offer Clues to Alzheimer’s and Aging.” Key evidence consisted of essays written by the nuns when they were young, which suggested that “ ‘idea density,’ many thoughts woven into a small number of words, [was] a trait correlating closely with nuns who later escaped Alzheimer’s.”

That study has come back to me often. Columnists who fasten their well-worn anti-Trump talking points to every news event in our ever-interesting world are not...