Rudolf Carnap an P.W. Bridgman, 14. April 1935 April 1935

Thank you very much for your kind letter of Sept. 19. I am very glad to see that you are interested in the writings of the Viennese CircleISchlick-Zirkel, Wiener Kreis and that you also – as we do – think that there is much in common between your views and ours.

Even in the point which you touch in your letter, there is, I think, more agreement than it might seem for the first look because we did not stress this point so much and perhaps not enough. That language is a device which is, as all practical devices, always imperfect, and therefore will not be perfectly appropriate to all possible situations, that is an opinion which we share with you. Just therefore we think that stating new and better language systems is one of the most important tasks of the logicians. Logic is a tool; yes, in our view it is nothing else than the system of rules of a certain language system. As there is not only one possible form for a knife, thus there is not only possible logic. For each purpose of cutting we have to look for the most appropriate form of knife or, if there is at present no suitable form, we have to try to make a new one, as appropriate as possible (i. e. as we succeed to find out in the moment), although never perfectly appropriate. Analogously for each purpose of expressing and describing facts we have to look for the most appropriate logic, that is for a language system as suitable as possible, though never perfect. Thus we agree with you in the opinion that a fixed system of language cannot be perfect; that always there might be found situations for which it is not sufficiently suitable. But then we should think, that in every such situation there is the necessity and also the possibility of improving the language system used, the logic applied. I do not know whether you think that there are or might be situations for which every possible logic would fail, that is: would be unable to make the necessary expression forms available. I am not sure whether this is so; I did not think enough about this question; but I have some doubts whether there could be such situations. On the other hand I admit that there may be situations (and perhaps all experiences have this character) which are inexhaustible in the sense that we could say more and more about the situation without ever coming to an end. This question however is not the same as that before, I think.

I am not sure whether I expressed my thoughts here in a sufficiently clear way, or rather, I am sure, I did not. I am afraid, letters are always a very insufficient method for scientific discussion. The more glad I am, that in the next year I shall have the opportunity to come to HarvardIHarvard University, Cambridge MA and, I hope, to speak with you. Because some weeks ago I got an invitation from the presidentPConant, James B., 1893–1978, am. Chemiker of the Harvard UniversityIHarvard University, Cambridge MA for participation in the Tercentenary (Sept. 1936) and in the ConferenceISymposium zum 300. Jubiläum Harvard, September 1936 connected with it. I shall be very happy to come.