I am not a person prone to smugness. When I say that my life is the sanest and gentlest a person in our times can hope to live, it is with gratitude, not self-satisfaction. My house is near the center of Oxford, a famously old and beautiful city, and I commute to work each morning on a bicycle alongside a quiet canal. The journey takes no more than seven minutes — eight or nine if I stop to admire the swans; I hardly remember what it is like to sit in traffic or to grind against a stranger on public transport.

I teach at Oxford University where I have a tenured job — a rare privilege in this day and age. The students are clever and hardworking, my colleagues considerate and sane, my days never less than interesting.

Work seldom ends after 7 p.m. On summer evenings, my partner and I often stroll along the Thames into Port Meadow, cross its 300 acres of ancient pasture, and eat in the village on the other side. The light in the meadow is gorgeous from May through September, turning the grass a luminous green I last saw in childhood dreams.

I have just resigned from this job and am giving up this life. In a couple of months, my partner and I will be moving to Johannesburg, South Africa, where I was born. It is a city that heaves with umbrage. "There is a daily, low-grade civil war at every stop street," the artist, William Kentridge, recently remarked. Sometimes, the war moves up a grade; many friends and family members have stared down a gun barrel over the years, and each act of violence is relived in conversation a hundred times over. It is a city where being white or well-heeled attracts some to beg from you and others to insult you, where life is so palpably unfair that the rich live in a state of astonishing denial while among the poor antipathy runs so deep that if you listen you can hear it hum.