What a delight to plan definitely on seeing you both in America next year! This has been our fondest wish for two years, and we are extremely happy and excited about finally seeing it realized. I wish it were happening this September, but that it is definitely fixed in the not distant future is splendid news.
It is, I should think, certain that in thus coming to America you will come to stay. There will unquestionably be offers. My chief hope, of course, is that you will stay at HarvardIHarvard University, Cambridge MA, so that the four of us can be neighbors: for it seems likely that I shall be continuing here.
My three-year research fellowship expires in June 1936, but I am assured (unofficially, at this early date) of a teaching position at HarvardIHarvard University, Cambridge MA afterward. Hence, barring an offer of far better pay elsewhere, we shall be living in CambridgeIUniversity of Cambridge, Cambridge UK when you come. We are looking forward keenly to meeting your boat and taking you home with us. You must be our guests!
Professor L. J. HendersonPHenderson, Lawrence Joseph, 1878–1942, am. Chemiker, distinguished as a biochemist but now interested chiefly in ParetoPPareto, Vilfredo, 1848–1923, ital. Soziologe, was the direct force behind your invitation to the tercentenary. He is one of the most influential figures behind the HarvardIHarvard University, Cambridge MA administration. I see him regularly at the weekly dinners of the Society of FellowsISociety of Fellows Harvard, Cambidge MA, and on those occasions I interested him in your work. He readily became interested, because his own attitude is extremely antimetaphysical and skeptical. (You, however, would find his state of mind unsatisfactorily confused and na\"ıve.) As a result he bought and read (in part) your Logische SyntaxB1934@Logische Syntax der Sprache, Wien, 1934 when it appeared; and it was he (and, independently, or Rafael DemosPDemos, Raphael S., 1891–1968, am. Philosoph)1Hsl. who suggested to the philosophy department last fall that I be asked to give some lectures on your doctrines. The particular set of tercentenary lectures in which yours will occur was a subsequent idea of his own, and a couple of months ago he consulted me on the notion of including you.
Another ally, valuable but somewhat less powerful than HendersonPHenderson, Lawrence Joseph, 1878–1942, am. Chemiker, is 🕮 Charles P. CurtisPCurtis, dilettante and prominent Boston lawyer, who is a trustee of HarvardIHarvard University, Cambridge MA. He is a follower of Henderson’sPHenderson, Lawrence Joseph, 1878–1942, am. Chemiker in the study of ParetoPPareto, Vilfredo, 1848–1923, ital. Soziologe, and co-author with HomansP in a recent popular book Introduction to ParetoB. Like HendersonPHenderson, Lawrence Joseph, 1878–1942, am. Chemiker he is a sponsor of the Society of FellowsISociety of Fellows Harvard, Cambidge MA, so that I see him each week. Like Henderson he became interested in your work and read the not too technical portions of the Logische SyntaxB1934@Logische Syntax der Sprache, Wien, 1934. He attended my lectures and is at present studying over the manuscript of them, together with your new Philosophy and Logical SyntaxB1934@Philosophy and Logical Syntax, London, 1935. He is very enthusiastic; and he has a vote and a persuasive voice in university policy. He, like HendersonPHenderson, Lawrence Joseph, 1878–1942, am. Chemiker, will be a strong factor in brightening the future.
Many thanks for the copy of your Philosophy and Logical SyntaxB1934@Philosophy and Logical Syntax, London, 1935, a very fine little book, very well written, and constituting an excellent simplified synopsis of your doctrine. The need of such a bookB1934@Philosophy and Logical Syntax, London, 1935 has been made known to me again and again since my lectures on your work: for laymen and semi-laymen have been asking to reread the manuscript of my lectures, and urging me to bring out a little non-technical book in English2Hsl., some sort of “Introduction to Carnap‚” serving the same purpose. Your Philosophy and Logical SyntaxB1934@Philosophy and Logical Syntax, London, 1935 is therefore good news to many.
Thanks also for the offprint of your valuable article “Die Antinomien etc.”B1934@„Die Antinomien und die Unvollständigkeit der Mathematik“, Monatshefte für Mathematik 41 (1), 1934, 263-284 I am also very glad to have the duplicate stock of ErkenntnisIErkenntnis, Zeitschrift papers; I am reserving them for as judicious distribution as possible, hoping to place them only where they will be studied and used most seriously. Incidentally I was happy to be able to appropriate a copy of the “Protokollsätze”B1932@„Über Protokollsätze“, Erkenntnis 3, 1932/33, 215–228 paper for myself for I had lacked that paper, and am anxious to keep my Carnap library as complete as possible.
Thanks, fourthly, for your painstaking and valuable commentary on my bookBQuine, Willard Van Orman!1934@A System of Logistic, Cambridge MA, 1934. I shall follow your numbering in commenting on the comments.
1)2) It would surely have been well to present a rigorous development of the formative rules. But the policy which, motivated by considerations of expository simplicity, I deliberately adopted in the book, was to present 🕮 as little in the way of rigorous (and laborious) metamathematical analysis as was compatible with moderately unconfused expression of the logical system. Such e. g. was my reason for using the intuitive blanks “—”, “- - -”, “…” etc. instead of introducing expression-variables. I even went so far as to suppress syntactic expressions in favor of quoted logical expressions in many cases where I knew it to be strictly (if trivially) incorrect from a subtly syntactical point of view. On the same score, like LewisPLewis, Clarence Irving, 1883–1964, am. Philosoph and PrincipiaBRussell, Bertrand, und Alfred North Whitehead!1910@Principia Mathematica, Cambridge UK, 1910–1913, 2. Aufl., 1925–1927, I left the notion of significance at an unanalyzed level of this sort; “expressions constructible in terms of the primitive signs, by the tacit but obvious rules of combination, restricted however by the conditions imposed by the theory of types”; and I did not deliver myself explicitly even to the above extent. My attitude was that any reader already syntactically oriented could supply the wanted rigor by a routine application of the general methods published by you, and, in a less thoroughgoing way, by GödelPGödel, Kurt, 1906–1978, öst.-am. Mathematiker, TarskiPTarski, Alfred, 1901–1983, poln.-am. Mathematiker und Logiker, etc.; and as for the not yet syntactically oriented reader, I was not concerned in this bookB with orienting him, nor did I want to exclude him by presupposing his orientation. But whether or not this elliptical procedure was ill-advised, my chief mistake was in not including the above remarks in the introduction!
3b) I do not see how this will make the convention on p. 44 unnecessary, for that convention is required by the rule of subsumption rather than substitution.
3c) Quite right! This of course is tied up with my above remarks on 1)2).
4) Since in my bookBQuine, Willard Van Orman!1934@A System of Logistic, Cambridge MA, 1934 I talk in a deliberatively quasi-syntactic idiom [because of what I have said concerning 1)2)], and thus discuss for the most part elements and operations rather than primitive symbols, I should prefer this third method of dealing with parentheses: Let the parentheses be part-of the symbolism of the primitive and defined operations –e. g. let the symbolism of ordination and abstraction be respectively “(…‚…)” and “Symbol(…)” rather than “ …‚…” and “Symbol(…)” and then let certain parentheses be 🕮 dropped by explicit convention. (I used this kind of procedure, different in detail, in my paper in last October’s Bull. Amer. Math. Soc.I)aOriginal eckige Klammer But it is true in any case that the point of view on p. 51 is bad; an unnecessarily evil result of the attitude explained above in re 1)2).
8) I am very much pleased by your suggestion to eliminate operation signs as far as possible in favor of class-signs; this would be a great advance in elegance, and would greatly simplify the syntax of the system and shorten the (mainly tacit) syntactical rules. I am not sure that this would be worth the price of an extra primitive operation (classial) correlation), but I should certainly favor carrying your process as far as it can be carried without paying that price. In any case the method could be applied to all operations defined after classial correlation, and definitions or primitives could be so shifted about and revised as to bring in classial correlation very early. Still, this compromise procedure would fall short of the highly desirable principle that all defined symbols be class constants. But in whatever way these considerations may balance, the direction (Richtung) suggested is an attractive one.
10) Thanks; I hadn’t yet found that misprint. Here are some more: p. 115, end of line 19, add “the”; p. 163, third from last line, omit first “of”; p. 187, fourth from last line, for “ “ put “ “;2 Mal gleiche Anführungszeichen!? p. 200, column 2, line 8, for “negates” put “negate”; ninth line from end, for “151” put “149”. Two of these mistakes I had corrected on the proofs, and the printer overlooked the corrections; these of course are especially annoying.
A fifth object of thanks is your kindness in writing a reviewB of my bookBQuine, Willard Van Orman!1934@A System of Logistic, Cambridge MA, 1934 for ErkenntnisIErkenntnis, Zeitschrift, of which I am very glad.
Three days ago I mailed you offprints of my reviewsB of PeircePPeirce, Charles Sanders, 1839–1914, am. Philosoph III and IVB.
You are kind to suggest sending me your extra copy of my bookBQuine, Willard Van Orman!1934@A System of Logistic, Cambridge MA, 1934. I should like very much to have it for my own shelf, for, strangely, I do not at present own a copy; I gave my last away and have not yet bought another. 🕮
I suppose there is even at this late date a slight possibility of your being given an American offer for the coming year. I like to hope so. But otherwise, since you must be here in any case in September 1936, can’t you come in June 1936 and spend the summer in America instead of in the Tatra or the Tyrol? Whether or not we shall be at HarvardIHarvard University, Cambridge MA after September 1936 (which, however, we almost certainly shall), in any case we shall be here that summer. We are impatient to see you.
As soon as our present lease expires (end of this August) we plan to move out of the city, much as you have done in Prague. We hope to move into an even less populous quarter, however, than Novi Motol; a definitely rural region. We must of course be within about thirty minutes’ transportation of the university, and I think that will be possible. Our reason for moving is that we (especially I) can no longer endure the noise of radios, barking dogs and swarms of children. Hence when you come you will find us much more pleasantly and comfortably situated than in our present crowded city flat. There will be room, isolation and fresh air, and we will be able to take walks over the New England countryside at a moment’s notice without any preliminary transportation. For convenience in getting to the university an automobile will be desirable; we shall probably have one by the time you come, and it will enable us all to make pleasant little trips together.
You will find a third QuinePQuine, Elizabeth, *1935, Tochter von Willard Van Orman und Naomi Quine when you come. NaomiPQuine, Naomi, 1907–1997, geb. Clayton, 1932–1947 verh. mit Willard Van Orman Quine expects a baby five months from now.
With heartiest regards to both, also from NaomiPQuine, Naomi, 1907–1997, geb. Clayton, 1932–1947 verh. mit Willard Van Orman Quine, and with an ‘auf Widersehen’ this time in a definiten Sprache‚
P.S. – In speaking of your work, in English, I always say “formative rule” and “transformative rule”, which strikes the English ear as more elegant than “formation rule” and “transformation rule”. Also I have tended of late to say “formal (or material) idiom”; the latter word emphasizes that it is a linguistic concept. However, “mode” is not unsatisfactory – indeed, I approved 🕮 “mode” in an earlier letter.
I see there are further points I have failed to touch, so I shall continue this postscript.
It is clear that the very slight change which you suggest for the last line of p. 178 of your SyntaxB1934@Logische Syntax der Sprache, Wien, 1934 completely surmounts the difficulty I had raised.
Whitehead’sPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph new scheme, though still fragmentary, has now been published in a fuller form than I had been able to give it in my short synopsis; namely, see Whitehead’sPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph articleB in MindIMind, Zeitschrift XLIII (NS) pp. 281-297. It is full of misprints, for WhiteheadPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph was too ill to read proofs when they reached them; but you will be able to decipher the errors –e. g. “\(\exists \)” should be inverted iota at top of p. 287; the sign of logical addition should be replaced by the sign of inclusion at various points on p. 286.
Although Whitehead’sPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph scheme depends (as does my LogisticBQuine, Willard Van Orman!1934@A System of Logistic, Cambridge MA, 1934) upon construing propositional identity in a much stronger way than as mere sameness of truth-value, still (as in my system) there is no trace of anything approaching Lewis’PLewis, Clarence Irving, 1883–1964, am. Philosoph modality functions. Perhaps his notion of propositional identity would (unlike mine) turn out to approach Lewis’PLewis, Clarence Irving, 1883–1964, am. Philosoph “strict equivalence” if WhiteheadPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph were to enlarge upon the topic; but this is purely speculative, since neither postulates nor discussion are as yet forthcoming to determine this aspect. Such verbal questions as I have put to WhiteheadPWhitehead, Alfred North, 1861–1947, brit.-am. Philosoph on the subject have led only into metaphysical mazes; yet he will no doubt purge the finished product of any considerable metaphysical ingredients, as he has hitherto done in his technical logical writings.
I am glad of your connection with MorrisPMorris, Charles W., 1901–1979, am. Philosoph, bis 1951 verh. mit Trude Morris, danach mit Ellen Ruth Morris of Chicago – his efforts will add to the chances of your being brought to America a year early. As to the year after next, of course, I am thoroughly confident that you will be here to stay.
PrallPPrall, David Wight, 1886–1940, am. Philosoph and I were of course both disappointed that he could not translate the SyntaxB1934@Logische Syntax der Sprache, Wien, 1934, but I gave him to understand fully that the decision was Ogden’sPOgden, Charles Kay, 1889–1957, brit. Linguist und Philosoph and counter to your wishes and protests.
I enclose corrected copies of your recent letters. Your English is becoming very good. Practically all the corrections are of idiom rather than grammar, and the idiom itself is vastly improved.
Following your kind suggestion I also enclose a copy of my last letter for correction of the German.
