BR TO R.F. ALFRED HOERNLÉ, 30 DEC. 1919
BRACERS 54146. TL(TC,X). Harvard U. Archives
Proofread by K. Blackwell

70 Overstrand Mansions,
Prince of Wales Road,
London, S.W. 111
30.12.19

Dear Professor Hoernlé

I sent to you today a cablegram expressing my very high opinion of Sheffer’s work. I worded the telegram as exactly as I could, not strengthening my praise on account of Sheffer’s situation. I enclose receipt (there are no night letters or deferred cables now).

I want to say as strongly as I can that I think the use which he makes of the concept of permutivity is exceedingly able and important. In the MS that I received, he has only made a beginning, but it is obvious that he can draw innumerable consequences and make great developments without much further trouble, whereas what he has done required a high order of original power. If by any chance he fails to retain his post at Harvard, I shall make a strong effort to secure him a post at Cambridge (to which I am returning in October), and I shall have great hopes of succeeding.

His work on postulates and inter-translatability is very interesting, but I should personally give a somewhat different interpretation to some of his results. I also disagree — though with no great confidence — with what he says towards the end of his paper as regards constants. It is here that he specially criticizes me, so I am not an unbiassed critic of his work.

I consider the problems which he has attacked the most important in mathematical logic, both technically and philosophically. I know from long experience how difficult they are. His work seems to me in part definitive and throughout highly fruitful. I am writing to him also on some points of detail.

Yours sincerely
<signed> Bertrand Russell

Copy of Telegram2 from Bertrand Russell Sheffer very important. Claims mainly admitted. Permutivity capable enormous development. Russell. Extract from a letter3 of Bernard Russell’s to H.J. Laski “I know Sheffer well. He was a pupil of mine and I saw much of his work both at that time and later. He has published discoveries in the algebra of logic which appear to me very important, as I have had occasion to state in print. He has work on hand now which, from what I know of it, appears likely to constitute a very notable advance. In my opinion, both from the point of view of ability and fruitfulness in research, any faculty in the world would be fortunate to include him. I suppose Harvard realises its good fortune in having him”.

• 1

  [document] Proofread against a photocopy of a typed copy of the original letter.

• 2

  Copy of Telegram Entered as BRACERS 54148.

• 3

  Extract from a letter Entered as BRACERS 55626, 15 Sept. 1919.