D O C U M E N T 4 5 1 M A R C H 1 9 2 9 4 0 3 and thus Because , therefore then Best regards from your A. Einstein Please send the manuscript[5] and this letter to me at the address Kocherthaler, Am Hirschsprung,[6] so that I can finish working out this matter without a lot of unnec- essary writing. 452. “Hamilton’s Principle and Unified Field Theory” [Berlin, before 18 March 1929][1] [See Doc. 459 in this volume for translation of the published version.] H h 1 2       1 4             – + = H H  g  h    1 2    2     – +    + = 1 h --H   1 2 --   1 2 --   – 1 2 --        –      + + = 1 h -- H   H   –          –      +   = 1 h --V         +         +   – antisymmetric in  and  0 V /  0  H   H   –  / 0.    –          +              