On verso of Casshyap's letter.

"Thank you for your interesting letter of November 8. So far as I can tell it will be quite convenient to see you on December 1, but you had better ring up, as you suggest, a few days beforehand. I think you would do well to tackle the first volume of Principia Mathematica which I do not think you would find difficult. You can skip the demonstrations which are only put in to confute the sceptics. No previous knowledge of any kind is required for reading the book."