Condolence & Memory Journal

I spent my sabbatical leave at Kent State University in 1992-1993.
I had this chance to be in his graduate course, and I learned many interesting material in Banach space theory. I owed him some part of my
Academic career. God rest him.

Posted by Jafar Zafarani - Isfahan, Iran, OH - Student   August 11, 2020

Sorry for your loss.
Joseph Diestel was a great Professor and better friend.
Joseph Diestel from KSU, was Visiting Professor at Central University of Venezuela for many periods and organizer of the International Research Workshop on Banach Space Theory held at Mérida (Venezuela) on 1992. Thanks to him for his many lectures delivered during the 90's and his valuable teachings, also in many conversations and personal communications.
May God bless you and your family in this time of sorrow,

Posted by Alexi Quevedo - Caracas - friend   June 28, 2018

My husband Doug and I were neighbors of the Diestel family, when living on Akron Blvd, many years ago when my husband student at KSU, I remember the children as well as Joe and Linda well, yes we tipped some beers with them, and as I recall Linda was a good cook. Always liked his story about never driving a vehicle and the baby chickens at the home of his grandparents, a story I am sure you know well. I echo sentiment below that yes you knew you were in greatness when with him. My best to all his heirs. Ursula and Doug

Posted by Ursula and Doug McCormick - Bedford, IN - friend   May 09, 2018

I only got to know prof. Diestel through his mathematical writing; an inspiration and a breath of fresh air. His was a life that touched many.

Posted by Ales Cerny - London, UK - Student   October 21, 2017

Sorry for your loss. Have not seen Joe since undergrad days at UD and studying math together and hanging out on Brown streedt. he was a great guy as an undergrad.

Posted by Bill Gottschall - Dayton, OH   September 26, 2017

In this sad occasion, I would like to express my sincere condolences to Professor Joseph Diestel's family and faculty members of Kent State University. We all admit that one of his capabilities was to persuade novice researchers in the area of Geometry of Banach spaces and generously provide them with new ideas.

I feel obliged to hereby pay tribute to him and his outstanding good human being.

Posted by Jafar Zafarani - Isfahan   September 10, 2017

Joe was the most inspiring of my many teachers. You just knew that you were in the presence of greatness and he was happy to share it with you. It must have been a real adjustment coming to Ireland, but it was not visible to us. What still awes me is the genius of the exam he set - I still have to think a little when I read it. The care he took to produce something that taught as well as tested was amazing. His warmth and generosity created a resource that I have drawn on for almost forty years. In that time our paths have crossed from time to time and I have always felt the richer for it.

Posted by Declan Quinn - Syracuse, NY - Friend   August 27, 2017

Joe taught me 40 years ago while he was on a Fulbright in Ireland. What a character! We'd never encountered anything like him. We'd recently seen One Flew Over the Cuckoo's Nest, and Joe's zest for life, smarts, and irreverence had me for one wondering if we were being educated on the finer points of mathematical analysis by our very own Jack Nicholson.

He seemed like the kind of guy you could trust with your life, or your future, and in years to follow this was confirmed when I observed his unswerving loyalty to (and concern for the welfare of) friends made in Dublin. It was great to reconnect with him a decade ago, and find that he'd lost none of his charm or sense of humour.

They say every memorial should include a theorem and here's one from a lecture of his that I've never forgotten: "A function is of bounded variation if and only if it's the difference of two increasing functions." Of course, Joe's boundless enthusiasm was the sum of his various passions (matters Banach, baseball, and beer, to name three).

I'm delighted to have experienced his existence, and as for his uniqueness, let's just agree that 'ní bheidh a leithéid arís ann'!

Joe, you were an inspiration and a gent. I'll miss you.

Posted by Colm Mulcahy - Student   August 26, 2017

I met Joe only at an extended family gathering. I was impressed . Please accept my deepest sympathy.

Posted by Tom Gauldin - Washington Court House, OH - Family   August 25, 2017

Joe was a brilliant man. He was generous and kind. A man who inspired students, attracted geniuses and welcomed anyone with a sense of humour to share in a world, gentler, more authentic and supportive than the usual one : Joe's World.
I'll miss you Joe - the world has dimmed with your passing.

Posted by Mark Leeney - Donegal, Ireland - Friend   August 25, 2017

My condolences go out to Joe's family.
It is a pleasure to have known Joe! He and I shared a love of baseball and Joe was one of the few who really knew and understood the intricacies of the game. Joe was the quintessential "Baseball Man", and loved all the tiny details that the true baseball guy knows, but can't be seen by the naked eye!
I wish I'd gotten the opportunity to discuss the details of statistical analytics being used by Big League teams now to evaluate players' contributions and value to his team!
Rest in peace, Joe! I was a real trip, "talkin' ball" with you!

Posted by Noel Blankenship - Kent, OH - Friend   August 24, 2017

Jim, so sorry for your family's loss. Your dad sounds a lot like you..great coach and good human being. Our prayers are with you at this difficult time.

Posted by Nancy, Alex, and Alex illitch - Green   August 23, 2017

Jim, Denise, Maddie and Alex;
Heartfelt condolences are coming your way. Dr. Diestel sounds truly amazing. That, I'm sure, comforts you now.
Mary Dixon and Reilly Dougherty

Posted by A friend   August 23, 2017

Offering our deepest sympathies during this time.

Posted by The Staff of Bissler & Sons Funeral Home - Kent, OH   August 23, 2017

Joe was a great friend, a colleague and a fun guy.
He filled the field of Mathematics with joy and happiness.
When I tried to negotiate his salary at Mizzou for a visiting pofessorship. He told me I need a salary to be enough for my three Bs
Banach Spaces
For pictures of Joe that I posted on Facebook, please see


Posted by Elias Saab - Columbia, MO - Friend   August 22, 2017


Joe, we will miss you and your legendary stories.

Posted by Beata Randrianantoanina - Oxford, OH - Friend   August 22, 2017

Joe was a force of nature. His generous spirit and intellectual curiosity were gifts to all who knew him. He was devoted to his family.... not only to his own children, but to his mathematical family as well. His capacity for fun was boundless, his humor legendary, his zest for life inspirational. He will be missed.

Posted by Sally Smith - Oxford, OH - Family Friend   August 22, 2017

To Lisa, Jim, Chris, Geoff, and their family members, I am so very sorry to hear of Uncle Joe's passing. I smile while reading of his achievements, and how his reach extended, as an integral catalyst to uplifting so many lives. You must be very proud of him. Your words honoring him are beautifully written. The greatest story teller I have ever met, will be missed. He was one of the good guys. Love you all.

Posted by Holly Donovan - Bellingham, WA - Family   August 21, 2017

I am so sorry for your loss. Joe was a great man and I will never forget his jokes. He enriched my life in so many ways. I am going to miss him.

Posted by Mienie De Kock - Harker Heights, TX - Student   August 21, 2017