John retired from the practice of law in 2011 and, shortly thereafter, located just outside of Cambridge, England. From 2011 through 2015, he wrote his first book, Limits of Science, published in 2016. Subsequent editions, updated through mid-2022, are entitled Important Things We Don't Know. Diagnosed with ALS in 2015 and confined to a wheelchair by 2018, John wrote his first collection of essays, Wanderings of a Captive Mind, published in 2021. This new, second set of essays was written, largely during 2021, entirely using just his eyes. They are by practical necessity shorter than, and without the many references of, the essays in his prior collection.

John explains:

"Now that I am 'immune' to embarrassment, I can 'speak'. I need not hide my opinions. I do not worry anymore about offending people (not so much anyway). I dealt with my prejudices through reason and reasoning. I 'thought' myself to acceptance and tolerance, even though I did not much like people. ...An old friend said, when reading Wanderings, that 'Although I have to admit that your points of view do not fall comfortably into a "PC compatible" category, I do not find them in the least 'offensive.' You have brought a fierce belief in rational argument to bear on subjects that are seldom considered appropriate to reasoned debate. At this point ... in my life, I do not share your faith in logical arguments.