University of Chicago Library

Guide to the Unity of Science Movement Records 1934-1968

© 2006 University of Chicago Library

Descriptive Summary


Unity of Science Movement. Records




1.5 linear ft. (3 boxes)


Special Collections Research Center
University of Chicago Library
1100 East 57th Street
Chicago, Illinois 60637 U.S.A.


The Unity of Science Movement, founded by sociologist Otto Neurath, sought a common empirical attitude toward all the sciences and strove to develop a single, comprehensive scientific language. Along with a philosophic program, the members of the movement undertook the publication of the International Encyclopedia of Unified Science. The collection contains correspondence, manuscripts, financial records, programs, reprints, a photograph, and newspaper clippings. Includes extensive correspondence of members involved in the movement, as well as organizational materials and abstracts from the International Congresses for the Unity of Science. Also includes material related to the International Encyclopedia of Unified Science. Correspondents include Percy W. Bridgman, Rudolph Carnap, John Dewey, Herbert Feigl, Philipp Frank, Joergen Joergensen, Victor Lenzen, Charles W. Morris, Otto Neurath, Hans Reichenbach, Louis Roughier, and Bertrand Russell.

Information on Use


No restrictions


When quoting material from this collection, the preferred citation is: Unity of Science Movement. Records,[Box #, Folder #], Special Collections Research Center, University of Chicago Library

Historical Note

The Unity of Science Movement was a philosophic program that developed from the positions of the "Vienna Circle" philosophers of the late 1920s. The movement's founder and chief promoter was the sociologist Otto Neurath; and Charles W. Morris of the University of Chicago and Rudolph Carnap were also very active in the group's administration. Phillip Frank, Hans Reichenbach, Louis Roughier, Joergen Joergensen, Herbert Feigl, Carl Hempel and Victor F. Lenzen also contributed to the literature of unified science, whose advocates sought a common empirical attitude towards all the sciences and strove to develop a single, comprehensive scientific language. The participants in the movement believed a unified philosophical and methodological foundation for the sciences could be constructed by these means, and by the careful excision from science of "metaphysical," i.e., nonempirical concepts.

Along with their philosophic program, the members of the movement undertook the publication of the International Encyclopedia of Unified Science. Otto Neurath began organizing this project in 1935 during the first of many International Congresses for the Unity of Science. Throughout the 1930s there was an outpouring of unified science literature from sources including the journal Erkenntnis (edited by Rudolph Carnap and Hans Reichenbach), the publication series Einheitswissenschaft, and the American journals Philosophy of Science and the Journal of Symbolic Logic. Though the initial interest in the movement among philosophers was strong, activity in the Unity of Science Movement was severely restricted by the outbreak of the Second World War. Only the first two of the planned 200 volumes of the Encyclopedia were ever published. The congresses were stopped in 1941, the last having been held at the University of Chicago. Neurath relocated in England during the war and died there in 1945. Many of the other European members of the movement immigrated to the United States and contributed to the development of American scientific philosophy in the 1950s and 1960s.

Scope Note


This series (Boxes 1-2) contains extensive correspondence among Neurath, Morris and Rudolph Carnap. Also included are letters from John Dewey, Ernest Nagel, Carl Hempel, Herbert Feigl, Hans Reichenbach, Phillip Frank and Bertrand Russell. The correspondence is arranged alphabetically by author, and the letters of Rudolph Carnap (1:4), Charles Morris (1:15-18, 2:1-4) and Otto Neurath (2:6-14) are chronologically arranged.


The second series (BOX 3) contains manuscripts from the planning of the congresses, as well as programs, announcements and abstracts from the 6th International Congress for the Unity of Science held at the University of Chicago in 1941.

Related Resources

The following related resources are located in the Department of Special Collections:


Letters to and from Charles W. Morris about the Unity of Science can be found in the papers of George Herbert Mead (IV:5), Louis Wirth (VIII:9) and in the Presidents' Papers, 1925-1945 (106:15). Many letters from Morris, Neurath and other members of the movement are in the papers of Morris Raphael Cohen.

Subject Headings


Series I: General Correspondence

Box 1   Folder 1


  • Alexander, Mary
  • Allende, Amadeo Baez
  • Amen, Elizabeth W.
  • Andrade, M. J.
Box 1   Folder 2


  • Bailey, David Algar
  • Bates, Marston
  • Baylis, C. A.
  • Bean, Donald
  • Bergmann, Gustav
  • Bichowsky, F. Russell
  • Black, Max
  • Blanco, A. E.
  • Bloomfield, Leonard
  • Bohnert, Herbert Gaylord
  • Bowen, Carroll G.
Box 1   Folder 3


  • Boyer, Edna D.
  • Bridgman, P. W.
  • Brosek, Josef
  • Brown, W. Sterry
  • Brunswik, Egon
  • Byrne, Lee
Box 1   Folder 4


  • Calderon, Baltasar Isaza
  • Carnap, Rudolph
Box 1   Folder 5


  • Carus, Elizabeth
  • Carver, Walte B.
  • Cattell, J. McKeen
  • Church, Alonzo
  • Churchman, C. West
  • Cohen, I. Bernard
  • Cohen, Morris R.
  • Conklin, E. G.
  • Copilowish, Irving M.
  • Cori, Carl F.
  • Courant, James B.
  • Creedy, F.
  • Curry, Haskell B.
Box 1   Folder 6


  • Dewey, John
  • Ducasse, C. J.
  • Eckart, Carl
  • Edel, Abraham
Box 1   Folder 7


  • Feigl, Herbert
  • Feuer, Lewis
  • Findley, S. Walker
  • Finlay-Freundlich, E.
  • Fitch, Frederic B.
Box 1   Folder 8


  • Frank, Phillip
  • Friederich, C. J.
  • Frost, Corinne
Box 1   Folder 9


  • Geiger, George R.
  • Gomperz, H.
  • Gregory, Ralph
  • Guttman, Norman
  • Halban, E.
  • Haskell, Edward
  • Hayakawa, S. I.
  • Hearst, John
  • Hemens, Rollin D.
  • Hempel, Carl G.
  • Hiller, Elizabeth
  • Hitzel, Florence
  • Hubbert, M. King
  • Hull, Clark L.
  • Hutchins, Robert M.
Box 1   Folder 10


  • Irwin, Mary
  • Jacobsen, Betty
  • Jennings, H. S.
  • Joergensen, Joergan
  • Jordan, W. K.
Box 1   Folder 11


  • Kaempffert, Waldemar
  • Kaufmann, Felix
  • Kaplan, Abraham
  • Kelsen, Hans
  • Kendig, M.
  • Kennedy, Gail
  • Kline, J. R.
  • Konvitz, Milton R.
  • Korn, Alejandro
Box 1   Folder 12


  • Korzybski, Alfred
  • Kracke, Virginia L.
  • Krusemen, W. M.
  • Kuhn, Thomas
Box 1   Folder 13


  • Laing, G. J.
  • Lashley, K. L.
  • Lenzen, Victor F.
  • Lepley, Ray
  • Lewin, Kurt
  • Lewis, C. I.
  • Lindeman, Hans A.
  • Lindsay, R. B.
  • Littauer, Sebastian B.
  • Lotz, John
Box 1   Folder 14


  • Mainx, Felix
  • Malisoff, W. M.
  • Manach, Jorge
  • Mendes, Murillo
  • Merton, Robert K.
  • Meyer, Adolph
  • Meyerhoff, Howard
  • Mills, C. Wright
  • Mises, R. von
  • Mitchell, Madeline M.
Box 1   Folder 15

Morris, Charles W., 1935-1936

Box 1   Folder 16

Morris, 1937

Box 1   Folder 17

Morris, 1938

Box 1   Folder 18

Morris, 1939-1940

Box 2   Folder 1

Morris, 1941

Box 2   Folder 2

Morris, 1942-1949

Box 2   Folder 3

Morris, 1950-1960

Box 2   Folder 4


  • Morris, 1961-1968
  • Moulton, F. R.
  • Mumford, Edward P.
Box 2   Folder 5


  • Nagel, Ernest
  • Neurath, Marie
Box 2   Folder 6

Neurath, Otto, 1934-1936

Box 2   Folder 7

Neurath, January-May 1937

Box 2   Folder 8

Neurath, June 1937

Box 2   Folder 9

Neurath, July-December 1937

Box 2   Folder 10

Neurath, January-March 1938

Box 2   Folder 11

Neurath, April-December 1938

Box 2   Folder 12

Neurath, Otto, January-May 1939

Box 2   Folder 13

Neurath, June-December 1939

Box 2   Folder 14


  • Neurath, 1940-1945
  • Noonan, Julia A.
Box 2   Folder 15


  • Oboukoff, Nicholas M.
  • Ogden, C. K.
  • Petri, W. A.
  • Quine, Willard Van Orman
  • Reichenbach, Hans
  • Reichenbach, Herman
  • Richards, I. A.
  • Richter, Anders
  • Ritter, William E.
  • Rogers, Walter S.
  • Roller, Duane
  • Rome, Sydney
  • Rose, Henry
  • Roughier, Louis
  • Rusk, George Y.
  • Russell, Bertrand
Box 2   Folder 16


  • Santillana, George de
  • Sarton, George
  • Schreier, Fritz
  • Seeger, Raymond
  • Segall, Harold N.
  • Senior, James K.
  • Shapiro, Meyer
  • Skomp, David C.
  • Stebbing, Susan
  • Stevens, S. S.
  • Stevenson, Charles L.
  • Stewart, John Q.
Box 2   Folder 17


  • Tarski, Alfred
  • Taylor, Raymond L.
  • Thompson, Laura
  • Thurstone, L. L.
  • Tintner, Gerhard
  • Tisdale, W. E.
  • Tyler, Ralph W.
Box 2   Folder 18


  • Vanduzen, Henry
  • Weaver, Warren
  • Wells, Rulon
  • Wells, W. F.
  • Wieck, Fred
  • Wieman, H. H.
  • Williams, Donald C.
  • Wirth, Louis
  • Wong, Lai-ngau M.
  • Woodger, J. H.
  • Woodward, Frederic
  • Zilsel, Edgar
  • Zilsel, Paul R.

Series II: Organizational Material

Box 3   Folder 1


  • Pre-Congress Conference, Prague, 1934; schedule, draft of publication materials
  • 1st International Congress of Scientific Philosophy, Paris, 1935; programs, abstracts, papers (by C. W. Morris), outlines of Congress management
Box 3   Folder 2

2nd, 3rd, and 4th International Congresses for the Unity of Science (Copenhagen, 1936; Paris, 1937; Cambridge, England, 1938); programs, organizational outlines

Box 3   Folder 3

5th International Congress for the Unity of Science, Cambridge, Massachusetts, 1939; programs, announcements, financial and registration records

Box 3   Folder 4

6th International Congress for the Unity of Science, Chicago, 1941; programs, announcements, registration records, press releases

Box 3   Folder 5-8

6th International Congress for the Unity of Science, abstracts of presented papers

Box 3   Folder 9

International Encyclopedia of Unified Science (IEUS); drafts of prospectus (1937), notes from members of Encyclopedia organization Committee

Box 3   Folder 10

International Encyclopedia of Unified Science (IEUS); drafts of prospectus (1937), drafts of encyclopedia introduction

Box 3   Folder 11

International Encyclopedia of Unified Science (IEUS); drafts of prospectus (1937), comments of encyclopedia monographs

Box 3   Folder 12

International Encyclopedia of Unified Science (IEUS); drafts of prospectus (1937), miscellaneous organizational material; proofs of prospectus, announcements, reviews, contract drafts, news clippings

Box 3   Folder 13

Miscellaneous; notes to the organization of the Institute for the Unity of Science, photograph from the 2nd Congress (Copenhagen 1936), memorial tribute to Phillip Frank