On the passing of time, the madness of World War 2, the cosmological constant and his personal contentment.

Writing exactly a month after the atomic bombing of Hiroshima, Einstein ruminates bitterly on the end of the war: he and Besso have lived long enough to see 'the wretched folly and depravity of the human beast. And there they are, still praying to a God who, if he existed and had created them, would actually have been solely responsible for their wretchedness'.

On his latest scientific work, Einstein is sticking to his old line, 'that considerations based on probability cannot take a primary place' in the approach to the quantum question: 'I have tried much and discarded much, indeed almost everything, as once in May, as we wandered homewards over the Kirchenfeldbrücke [in Berne]. How short this personal existence is, measured against the great task! But already the chase alone compensates for all the trouble, and the graveyard of buried hopes doesn't frighten me. I prefer hard granite to all the ephemeral bustle in the human sphere, in which nothing endures'.

Einstein is pleased to hear that Besso has read his remarks on the 'cosmological problem': 'I have recently found that the gravitational field surrounding a star in an expanding universe is not at all influenced in its structure by the existence of the expansion. This result shows that the often supposed relationship between the cosmological and the molecular constant represents a hopeless objective – a result which I had absolutely not expected'.

Einstein has heard of the death of Besso's wife, Anna, and seeks to comfort him with the thought that he will come to value the solitude into which he has been thrust. Besso's grandson is thinking of emigrating to pursue an academic career in the United States. Einstein warns that 'America appears today from the distance with a halo', but that seen from within life can be hard graft: academic institutions are in many respects inadequate, and the competition for places is intense, worsened by anti-Semitism which is 'cloaked, but strong'. Einstein's own life, however, is very contented: 'I chew my cabbage undisturbed and need worry about no one ... Work fills me with the same power as in my young days'. He has valuable young assistants, and never has to attend congresses, other than the occasional 'rally' at which he is wheeled out as 'an old pom-pom or worn-out eminence'. For the rest, 'I sail daily in the summer in my little sailing boat, play a lot of music, almost exclusively alone, and read besides work many fine books': his companion in reading has in recent years been his sister Maja, although she is shortly to return to the European surroundings to which she is so attached.

In the event, Maja Einstein's return home was postponed, and a stroke in the following year prevented her from ever returning to Europe.