BR TO LEON CHWISTEK, 29 JAN. 1925
BRACERS 57259. ALS. Polish Acad. Sci(s)
Proofread by A.G. Bone

<letterhead>
31 Sydney Street
London. S.W. 3.
29.1.25

Dear Dr. Chwistek

I must apologize for having left your letter so long unanswered; illness and press of business were the reason. The “Zeitschrift für exacte Philosophie” has not yet begun to appear, but I understand that when it does it will print your article, though the editors seem somewhat afraid of mathematical logic.

Your “Theory of Constructive Types” is very interesting, and a valuable piece of work. My own view is that it is desirable to work out various hypotheses, before deciding which to adopt; I am as yet filled with doubt. My feeling is that we shall not arrive at a real solution until we have investigated the nature and principles of symbolism much more thoroughly than has hitherto been done. I cannot at present write to you in more detail, as I have no time for mathematical logic in the winter. But I emphatically regard your work as interesting and valuable.

With all best wishes,

Yours very truly
Bertrand Russell.