FOM: Wittgenstein and Brouwer

[Paolo Mancosu]

Tennant recalls having seen either a diary entry or a letter in the
Carnap archive concerning Wittgenstein's reaction to Brouwer. However,
this cannot be Carnap's report of the event  (and thus hardly a diary
entry) since Carnap was absent from Vienna, due to illness, from Spring
1927 until April 1928. He did not attend Brouwer's lectures (Brouwer
spoke in March 1928). Of course, Wittgenstein's reaction might well be
described in a letter to Carnap.
Concerning Goedel's reaction to Brouwer there is an interesting entry in
Carnap's diary (dated December 23, 1929):
"5 3/4 - 8 1/2 Uhr Goedel. Ueber Unerschoepflichkeit der Mathematik
(siehe besonders Blatt). Er ist durch Brouwers Wiener Vortrag zu diesen
Gedanken angeregt worden. Die Mathematik ist nicht restlos
formalisierbar. Er scheint recht zu haben."
 

(The above information is taken from Eckehart Köhler, Gödel und der
Wiener Kreis, in Paul Kruntorad, ed., Jour Fixe der Vernunft,
Hölder-Pichler-Tempsky, Wien, 1991, pp.127-158. The quote in on p.138)

Paolo Mancosu