September 16, 1947 Dear Doctor Heidelberger: I have just read your Presidential Address to the American Association of Immunologists on "Science, Freedom, and Peace". This is a stirring challenge, and I hope sincerely that you will have the satisfaction of wide appreciation and following. It is my opinion that it is necessary for all scientists to eschew secrecy at once. We should under no circumstance engage in secret undertakings, and it should be clearly understood that the result of our efforts are to be made public as soon as convenient and as soon as they are in proper order. Science implies freedom. It is the most important unifying force which we can develop in the world today. I do hope that you will continue your exhortations on this theme. I hope further that you will find an enthusiastic following from your colleagues. At least we will do our share in this part of the country! With cordial best wishes, Chauncey D. Leake Vice-President