The rain had just stopped and the air was infused with the invigorating smell of wet earth and pine trees.

Our last exchange over the telephone is the only evidence of Petros Papachristos' mystery-solution to Goldbach's Conjecture.

Unlike Pierre de Fermat's illustrious marginal note, however, it is extremely unlikely that my uncle's demonstratio mirabilis of his famous problem will tempt a host of mathematical hopefuls to attempt to reproduce it. (No rise in the price of beans is expected.) This is as it should be. Fermat's sanity was never in question; no one ever had reason to believe he was in anything less than total possession of his senses when he stated his Last Theorem. Unfortunately, the same cannot be said of my Uncle Petros. When he announced his triumph to me he was probably as mad as a harter. His last words were uttered in a state of terminal confusion, the total relinquishment of logic, the Night of Reason that dimmed the light of his final moments. It would thus be extremely unfair to have him posthumously declared a charlatan by attributing a serious intention to a declaration obviously made in a half-delirious state, his brain most probably already ravaged by the stroke that, a short while later, killed him.

So: did Petros Papachristos prove Goldbach's Conjecture in his final moments? The wish to protect his memory from any chance of ridicule obliges me to state it as unequivocally as possible: the official answer must be 'No'. (My own opinion need not concern mathematical history – I will therefore keep it to myself.)

The funeral was strictly family, with only a wreath and a single representative from the Hellenic Mathematical Society.

The epitaph later carved on Petros Papachristos' tomb, below the dates marking the limits of his earthly existence, was chosen by me, after I had overcome the initial objections of the family elders. They form one further addition to the collection of posthumous messages that make the First Cemetery of Athens one of the world's most poetic:

EVERY EVEN NUMBER GREATER THAN 2

IS THE SUM OF TWO PRIMES

At the time this book was completed, Goldbach's Conjecture was two hundred and fifty years old. To this day it remains unproven.

I wish to thank Professors Ken Ribet and Keith Conrad, who carefully read the revised manuscript and corrected numerous mistakes, as well as Dr Kevin Buzzard for the clarification of various points – obviously, any remaining mathematical flaws are my own. Also my sister, Cali Doxiadis, for her invaluable linguistic and editorial advice.

APOSTOLOS DOXIADIS