“Anyone's demise or vanishment is in some small way tragic but the word "tragedy" requires greater measure for its use. … Van' s great mind now gone. Tragedy.”

In his introduction "Van is Here, But Van is Gone" to Futures Past: The Best Short Fiction of A. E. van Vogt (July 1999) http://www.sfrevu.com/ISSUES/2000/ARTICLES/20000128-03.htm
Context: Alfred E. van Vogt, since the appearance of his first two stories — "Black Destroyer" and "Discord in Scarlet" (Astounding Science Fiction, July and December 1939) the most memorable debut in the long history of the genre — has been a giant. The words seminal and germinal leap to mind. Sadly, at this juncture. the words tragedy and farewell also insinuate themselves. … Van is still with us, as I write this, in June of 1999, slightly less than fifty years since I first encountered van Vogt prose in a January 1950 issue of Startling Stories, but Van is gone. He is no longer with us. … Because the great and fecund mind of A. E. van Vogt has fallen into the clutches of that pulp thriller demon, Alzheimer's. Van is gone. … Anyone's demise or vanishment is in some small way tragic but the word "tragedy" requires greater measure for its use. … Van' s great mind now gone. Tragedy.
The ultimate tragic impropriety visited on as good a man as ever lived. A gentle. soft spoken man who was filled with ideas and humor and courtesy and kindness. Not even those who were not aficionados of Van's writing could muster a harsh word about him as a human being. He was as he remains now, quietly and purposefully, a gentleman.
But make no mistake about this: the last few decades for him were marred by the perfidious and even mean spirited and sometimes criminal acts of poltroons and self-aggrandizing mountebanks and piss-ants into whose clutches he fell just before the thug Alzheimer got him. … I came late to the friendship with Van and Lydia. Perhaps only twenty-five or so years. But the friendship continues, and at least I was able to make enough noise to get Van the Science Fiction Writers of America Grand Master Award, which was presented to him in full ceremony during one of the last moments when he was cogent and clearheaded enough understand that finally, as last, dragged kicking and screaming to honor him, the generation that learned from what he did and what he had created had, at last, fessed up to his importance.
Naturally, others took credit for his getting the award. They postured and spewed all the right platitudes. Some of them were the same ones who had said to me — during the five years it took to get them to act honorably — "we'd have given it to him sooner if you hadn't made such a fuss." Yeah. Sure. And pandas'll fly out of my ass.