The central question in the Book of Job is: "Why do the righteous suffer?" I found myself asking this when I finished reading Steve Jobs' moving letter of resignation from his position as CEO of Apple.
By most accounts a generous boss and kind colleague, Jobs felt unable to continue in the post because of ill health, having been diagnosed with pancreatic cancer in 2004 and given a liver transplant in 2009. His gaunt features, accentuated by the turtleneck jumpers he favours, belied a man enduring daily pain.
It has felt for several years as if the world of information technology itself was run according to a bible called the Book of Jobs. I can't think of any living man who so profoundly changed so many lives. Manmohan Singh, the Indian Prime Minister, has probably alleviated more suffering and poverty than anyone else; Nelson Mandela inspired a people to conquer apartheid; and Mark Zuckerberg redefined friendship. But for sheer scale of impact, both global and domestic, Jobs trumps them all. The worlds of business, film, music, television and computing have been revolutionised by gadgetry and software for which he was the intellectual champion.
Matthew Arnold said a literary masterpiece was the concurrence of two powers, that of the man and that of the moment. Jobs' extraordinary influence is similarly the concurrence of his creative genius with the age of digital information and the internet.
Apple will, of course, bear his heavy imprint as long as the company exists - not least because he is continuing as chairman. But if his influence on our lives has passed its peak, this may be the time to reflect on what he has taught us. I'd pick out two things.
First, Apple has excelled not by developing new product categories, but rather by improving existing ones: this was the genius of the Macintosh, iPod, and iPhone. Jobs understands there is no such thing as an original idea.
Second, the importance of stamina. Variously dismissed as bonkers, Bill Gates Mark II, and an invalid with only months to live, he ploughed on, driven by conviction about the role of technology in our lives. This makes him both the greatest entrepreneur of his generation, and an inspiration to rejects the world over. Long may his spirit endure.
Simon Kelner is away.