By common consent Isaiah Berlin enjoyed a happy old age. The autumn of his life was a time of serenity. But serenity in old age is a philosophical puzzle. Why did he manage to avoid the shipwreck which is the more common fate of us all? The obvious answer is that he was exceedingly fortunate. He married happily, late in life, and he enjoyed good health, good fortune and a growing reputation. His life between 1975, when he retired from the Presidency of Wolfson College, Oxford, and his death in 1997, was a time both of ease and increasing public recognition. Berlin's editor, Henry Hardy, began editing and republishing his previously unpublished essays and lectures, and this transformed Berlin's reputation, giving the lie to Maurice Bowra's joke that like our Lord and Socrates, Berlin talked much but published little. He lived long enough to see his reputation, which had been in relative eclipse, blossom into what he referred to as a ‘posthumous fame’.

Certainly, Berlin's serenity in his final years owed a great deal to good fortune. But there are temperaments which frown even when fortune shines, and even those with sunny temperaments find mortal decline a depressing experience. So Berlin's serenity is worth trying to explain, both for what it tells us about him and for what it tells us about how to face our own ageing. I want to ask whether his serenity was a matter of temperament or a result of conviction, whether it was a capacity he inherited or a goal he achieved, and in particular whether his convictions – liberal, sceptical, agnostic and moderate – helped to fortify him against the ordeals of later life.

Being philosophical about old age implies being reconciled or being resigned or some combination of the two. I want to ask whether Isaiah was resigned or reconciled and in what sense philosophy helped him to be philosophical in either of these senses.

From Socrates onwards, philosophy – especially the Stoic tradition – has made the question of how to die well one of its central preoccupations. Indeed until philosophers became academic specialists devoted to instruction of the young and maintenance of that walled garden known as professional philosophy – in other words until the second half of the nineteenth century – one of the central tests of a philosophy was whether it helped its adherents to live and die in an instructively rational and inspirational fashion.