On spinor theory, the schizophrenia of his younger son, and solutions for the economic crisis.

Einstein is working with Walter Mayer on the theory of spinors: 'We have already been able to illuminate the mathematical structures. We are still far from a grasp of the physics – much further than people think at present. Above all, I am as much convinced as before that the search for an essentially statistical theory [of quanta] will fail'.

Besso has been pleading with Einstein on behalf of his younger son, Eduard (known as 'Tete' or 'Tetel', who had been diagnosed with schizophrenia two years earlier, and was to spend much of the rest of his life in an asylum close to Zurich): Einstein assures his friend that he has not taken his intervention badly, and that he has in fact invited Eduard to come with him to Princeton the following year – Einstein's immediate trip to California would not be suitable: 'Sadly everything points to the fact that his heavy family heredity is having a decisive effect on him. I have already seen it coming since Tetel's childhood, slowly but irresistibly'. He also feels that Eduard is suffering from the bad influence of his older brother Hans Albert and his wife Frieda (of whom Einstein strongly disapproved at this date), and he is worried that they will seek to take over the entire inheritance after Einstein's death. Returning to the subject of the economic crisis (see preceding lot), Einstein fears that the problem is an excessive supply of unskilled labour, remarking 'I am neither socialist nor communist', and he doubts the efficacy of a planned economy, but some state intervention is required to maintain salaries and therefore consumption, otherwise the consequences for the unskilled working classes in particular will be catastrophic.

On 6 December 1932 Einstein left his beloved house in Caputh for his trip to California: Hitler's rise to power occurred before his return, and he was never to come back to Germany – nor to Zurich to see his son Eduard – again.