Norway provided Wittgenstein with the solitude he thought necessary for work on logic. Together with his close friend David Pinsent he had found a place to vacation at Öystese, a tiny village in a little bay on the Hardangerfjord with majestic hills rising behind. When he returned to Cambridge on 2 October, he told Russell of his firm intention to leave Cambridge and live in Norway. Russell wrote to Lucy Donnelly on October of 1913:
Then my Austrian, Wittgenstein, burst in like a whirlwind, just back from Norway, and determined to return there at once to live in compete solitude until he has solved all the problems of logic. I said it would be dark, and he said he hated daylight. I said it would be lonely, and he said he prostituted his mind talking to intelligent people. I said he was mad, and he said God preserve him from sanity. (God certainly will.)
The ideas germinated in the year Wittgenstein spent in Norway would become a centerpiece of Wittgenstein's philosophy of logic – the doctrine that logic consists of tautologies.
August 1913 dates the following entry in Pinsent's diary: “It is probable that the first volume of Principia will have to be re-written, and Wittgenstein may write himself the first eleven chapters. That is a splendid triumph for him!” The catalyst for Wittgenstein seems to have been that Russell came to know of Sheffer's result that all the quantifier-free formulas of Principia's sentential calculus can be expressed via one logical connective – the Sheffer stroke.