There are notes in BR's hand of possible topics at the foot of the letter:

? Effect of Science on Social Institutions [B&R C23.42]
✓ Machines & the Emotions [C24.16]
Industrializing the Far East
✓ Psychology & Politics [C24.07]
✓ Shall State physicians control our passions?
Does matter exist?

[BR's check mark seems to imply that he delivered the title, but there is no trace of the 3rd checked title. Missing from the list is B&R C23.35, "An Essay on Behaviourism", which he published in Vanity Fair in October 1923.]