Ludwig Wittgenstein me." Wittgenstein had only maintained contact with Fouracre from Guy's hospital who had joined the army in 1943 after his marriage, only returning in 1947. Wittgenstein maintained frequent correspondence with Fouracre during his time away displaying a desire for Fouracre to return home urgently from the war. In May 1947, Wittgenstein addressed a group of Oxford philosophers for the first time at the Jowett Society. The discussion was on the validity of Descartes' Cogito ergo sum where Wittgenstein ignored the question and applied his own philosophical method. Harold Arthur Prichard who attended the event was not pleased with Wittgenstein's methods;Wittgenstein:
Descartes number only one currently known. If is an odd almost perfect number, that is, and is taken as a 'spoof' prime, then is a Descartes number, since . If were prime, would be an odd perfect number. Descartes number In number theory, a Descartes number is an odd number which would have been an odd perfect number, if one of its composite factors were prime. They are named after René Descartes who observed that the number would be an odd perfect number if only were a prime number, since the sum-of-divisors function for would satisfy, if 22021 were prime, where we