Thank you for your detailed letter of December 22nd. I am hurrying to answer it because we shall leave here (Texas) in a few days in order to go to the Mayo Clinic (in Minnesota) – this is the most famous hospital in the U.S. – to get their opinion about my back since it does not improve at all. Normally I have no pain, but now much of the Rockefeller-year is over and I have to think of being able to teach again; as I am today – and have been for the past 7 months – I could not teach, and therefore I have decided to make this long pilgrimage to Mayo’s. I don’t know yet that they will be able to do something for me – some similar cases have been helped by an operation – but it always depends what they think of the individual case. Well, we shall see.
I had a letter from the Harvard Press in October in which they said that they had no confirmation from the Oxford Press that the shipment containing copies of my book had arrived but that they felt certain that it had arrived because otherwise they would have been notified by the Oxford Press. Therefore I am surprised to learn from your letter that the Oxford Press has no copies. Anyway, I wrote yesterday to the Harvard Press, asking them to send you a copy, registered, if they have not already done so.
I regret very much that you are so intolerant with respect to some ideas of people who share with us the fundamental empiricist attitude. In the case of PopperPPopper, Karl Raimund, 1902–1994, öst.-brit. Philosoph, verh. mit Josefine Popper, I believe your reaction is chiefly caused by the fact that he criticized the Vienna Circle quite unnecessarily. He was overcritical and so you are now. Even when he wrote the book he was in agreement with us on most fundamental points. When later he came into personal contact with us the agreement became even more strong and conscious to him. Some of his views which you criticize, e. g. the refutability of hypotheses, have the same defects – and, I think, the same merits – as many of our earlier views: they might be taken as first approximations but closer inspection shows that they are not entirely adequate but must be replaced by better approximations. I suppose that the same holds for many of our present views, including mine, where we do not see today how they should and can be improved. In the case of some of your views which are not shared by most of the people in our movement I often defend them in just the same way: I admit to those who criticize them that the formulations are not quite adequate but I point to the fact that they may be taken as first approximations. I like to defend your views but sometimes you make it, by Jove, hard for me to do so when you stubbornly stick to your old formulations years after they have been shown to you to be inadequate (e. g. “No facts, only statements”, your form of protocol sentences, “the semantical concept of truth is only applicable to calculi not to the language of science”). The views of all of us within the movement of empiricism do of course differ more or less from each other. I think for the sake of the movement it would be 🕮{}much better if we were more tolerant towards each other. If your intolerance would become the general custom, then I am afraid you would be among the first to be declared a heretic and excommunicated. By tolerance, of course, I do not mean acceptance of each other’s views. The differences of opinion should and will be discussed. But this discussion is not helped by labelling the views of the others as nonempiricist and metaphysical.
When you read my “Semantics” and especially when you write to me about it, please keep in mind that the semantical concepts used there are meant for application also to the language of science, especially the concepts “true”, “L-true”, and similar ones. In this book I did not apply them to science and I made only brief remarks concerning their applicability. I regret now that I did not emphasize this point more, especially after reading Nagel’sPNagel, Ernest, 1901–1985, am. Philosoph, verh. mit Edith Nagel review in the Journalof Philosophy who in this and some other respects misunderstood the intention of the book, and after reading your remark about TarskiPTarski, Alfred, 1901–1983, poln.-am. Mathematiker und Logiker making things independent of the application. I do not know exactly what TarskiPTarski, Alfred, 1901–1983, poln.-am. Mathematiker und Logiker thinks of the question of applicability. In any case, the concept of truth as I deal with it is meant as a systematization of the inexact term “true” as used by scientists and in everyday life.
What became of Waismann’sPWaismann, Friedrich, 1896–1959, öst.-brit. Philosoph, verh. mit Hermine Waismann MS? Did you not have it once for examination with respect to the question of publication? I should have liked to see it.
We are very glad to hear that you and MaryPNeurath, Marie, 1898–1986, geb. Reidemeister, auch Reidemeisterin, Mieze, MR, Mary, dt.-brit. Pädagogin und Sozialwiss., Schwester von Kurt Reidemeister, heiratete 1941 Otto Neurath are again successfully working in your Isotype Institute, that you are rebuilding your library, have good collaborators and friends. Now that the military situation looks more hopeful our thoughts turn more and more to the question of the kind of peace that will emerge. And there are sometimes reasons to worry. Or do you think we may be hopeful here too?
ReichenbachPReichenbach, Hans, 1891–1953, dt.-am. Philosoph wrote that GomperzPGomperz, Heinrich, 1873–1942, öst.-am. Philosoph, verh. mit Adele Gomperz died in December.
When returning to Chicago, I shall probably teach elementary mathematics instead of philosophy! The conversion of our colleges for war needs has not left many students in philosophy, whereas many more (in Chicago we have a special instruction center for Navy-communication-men) will need mathematics. Therefore I have volunteered to switch over.
With warmest greetings from both of us to the two of you,
