"Sat evg." "This morning I went on till Whitehead came about 11. Since then we have been discussing and arguing till we were both nearly dead. I took the opportunity of making him read Wittgenstein's work with my exegesis—he thinks just as well of it as I do. Whitehead has done stacks of good work on geometry, which we talked about; and then I explained my ideas on matter, which pleased him. Our world is buzzing and very encouraging."