\brief{Rudolf Carnap an W.V.O. Quine, 5. Mai 1935}{Mai 1935}

%Prof. Dr. Rudolf Carnap

%Prag XVII

%Pod Homolkou 146

%May, 5, 1935.

\anrede{Dear \textit{Quine},}

\haupttext{Your letter of March\,31 was very satisfying for me, as well by your optimism concerning my further chances in USA as by
your great personal kindness.

We too had already considered the plan of coming some time before August 1936 to the US in order to spend the summer
there, to see friends and to learn English. Your very kind proposal gives us a strong stimulus in this direction.

I hope with you that the Harvard\II{\harvard} invitation will have a strong effect on other American universities, and I suppose,
that this effect will be strengthened by the fact that, according to the President's\IN{\praesidentharvard} letter, the Honorary Doctorate of
Science will be conferred upon me. Do I owe this also to Prof. Henderson\IN{\henderson}?

You have rendered an extremely effective help by interesting Prof. Henderson\IN{\henderson} and Mr. Curtis\IN{\curtis} on my work. Would you,
please, give me their addresses and those of other people which you would consider to be worth for sending separata? It
would be very useful for me, if you gave me kind suggestions as to which separata would be of interest for each of them.
You may simply note the numbers, according to the following list:

*(5. Physikalische Begriffsbildung.)\IC{\physikalischebegriffsbildung}

*(7. Der Logische Aufbau der Welt.)\IC{\konstitutionstheorie}

*(8. Scheinprobleme.)\IC{\scheinprobleme}

*(9. Abriß der Logistik.)\IC{\logistik}

*13 F. L'Ancienne et la Nouvelle Logique. (Translation of Erkenntnis I, p.\,12.)\IC{\alteneuelogik}

*19 F. La Science et la Metaphysique. (Translation of Erkenntnis II, p.\,219)\IC{\ueberwindungdermetaphysik}. (I have no more
offprints of the German originals 13 and 19.)

*20 E. \uline{Unity of Science}\IC{\unityofscience}.

21. Psychologie in physikalischer Sprache. (Erkenntnis)\IC{\psychologiesprache}

22. Erwiderung auf Zilsel und Dunker. ( `` )\IC{\erwiderung}

23. Protokollsätze. ( `` )\IC{\protokollsaetze} \neueseite{}

26. \uline{On the Character of Philos. Problems}. (In: Phil.of Science)\IC{\problemederphilosophieaufsatz}

* 28. Logische Syntax der Sprache\IC{\logischesyntax}

* 31. \uline{Philosophy and Logical Syntax}\IC{\londonervortraege}.

34. Formalwissenschaft und Realwissenschaft. (Just appeared in ``Erkenntnis''; offprint has been sent to you.)\IC{\vortragvorkonferenz}

35. Les Concepts Psychologiques et les Concepts Physiques. (Is to appear soon in the French
Periodical ``Synth\`{e}se'').\IC{\franzoesischeraufsatz}

* Appeared not in periodicals, but as independent issues. Please note also, if somebody has already something of the
list (bought, or as subscriber of the journal, or offprint given by you.) I would like to keep my card-index complete;
everybody who has offprints of mine, is contained in it.

Please write me whether you yourself have all of the list. Perhaps not (5)\IC{\physikalischebegriffsbildung} and (8)\IC{\scheinprobleme} (if my card-index is right); if so, I
shall send them. And would you like to have (13 F)\IC{\alteneuelogik} and (19 F)\IC{\ueberwindungdermetaphysik} in French?

In the next time you will receive an offprint of a paper (33) ``Über ein Gültigkeitskriterium. \ldots{}''.\IC{\gueltigkeitskriterium} The contents of
this paper and the previous one (32) ``Antinomien''\IC{\msantinomien} will be contained in the English translation of ``Syntax''\IC{\logischesyntaxenglisch}. Therefore
in general I do not send offprints of these papers to American readers, with few exceptions.

May I perhaps read a copy of the manuscript of your lectures\IW{}?

The English translation of ``Syntax''\IC{\logischesyntaxenglisch} is said to be nearly complete. Ogden\IN{\ogden} sent me Ch.\,I and II of it. I had to spend
much work in revising and correcting them; I found a lot of mistakes, misunderstandings and unsuitable expressions.
Therefore I suggested Ogden\IN{\ogden} once more most urgently to take another translator. But he answered that this were
impossible; he went through all my corrections and asserts that there were only 5 (!) real mistakes. He promises that the
rest will be examined very carefully before it comes to me. Thus I hope that the translation after all will not be too
bad. You may imagine that after these experiences \neueseite{} I am still more angry about that Ogden\IN{\ogden} did not accept the proposal of
Prall\IN{\prall} in January.

Concerning my remarks on your book\IW{\quinebuch}. 1)2). You may be right in making the syntactic explanations of your system as simple
as possible, considering the class of supposed readers. Your use of the intuitive blanks ``-\,-\,-'', ``\ldots{}'' etc. instead
of special syntactical symbols seems to me very suitable for the purpose. Nevertheless I think it would be desirable or
even necessary to state formation rules; that may be done in a simple form, using your blanks, e.\,g.: ``Every class
expression has one of the following forms: 1.) variable in class-position, 2.) ``$\hat{x}(...)$'' where `` \ldots{}'' has sentencial
form, 3.) ``\ldots{}''. And analogously for ``sentence''. Then it will be easy to formulate the rule of substitution so as
to avoid the contradiction 3c.

3b). I am not quite sure whether or not my considerations are right, but still the following seems to me to be the case:

\blockade{folgender Abschnitt: Inhalt ok, Formatierung nicht}

A) The addition of ``every free'' in the definition of ``substitution'' p.\,142 is necessary; for we do not wish to call
the transformation of

(1) $...\alpha...\hat{\alpha}(--\alpha--)$\blockade{kurze Bindestriche werden in Formelumgebung 2 Mal ,,minus``}

into

(2a) $...V...\hat{\alpha}(--V--)$

or into

(2b) $...V...\hat{V}(--V--)$

a substitution.

B) When the mentioned addition is made, the word ``free'' may be left out in the rule of substitution.

C) If that addition is made and the convention at the end of p.\,44 is left out, a theorem of the form

(3) $[\alpha], \hat{x}(- - \hat{x}(...)- -)$

does not seem to me to be dangerously ambiguous. Or do you think, it is so? Could you perhaps give me an \neueseite{} example of a
contradiction resulting from it? or a proof of a theorem which we should not wish to be demonstrable?

My best thanks for your reviews\IW{} \IW{} of Pierce\IN{\peirce} III\IW{} and IV\IW{}.

Simultaneously I send you your book\IW{\quinebuch}.

I proposed the terms ``formative rules'' and ``transformative r[ules]'' to the translator already in a letter of June 1934;
but she did not accept them. As you find them preferable, I too shall use them in the future.

I enclose your German letter with my corrections. If you wish to exercise your German I am of course always ready for
correcting German letters; it does not take more than a minute.

We are glad that in the next year we shall find you as a triad. We send Naomi our most hearty wishes for her hard
examination in August; that is more than writing logic. And we are glad too that you will soon be living on the
countryside and have it more quiet. That will be good for health and work.

With cordial greetings 2 $\rightarrow$ 2,}

\grussformel{Yours\\
R. Carnap}

\ebericht{Brief, msl., 4 Seiten, \href{https://doi.org/10.48666/854832}{WQ}; Briefkopf: gedr. \original{Prof. Dr. Rudolf Carnap \,/\, Prag XVII. \,/\, Pod Homolkou 146}, msl. \original{May, 5, 1935}.}