“The great objects which presented themselves [to the Constitutional Convention] … formed a task more difficult than can be well conceived by those who were not concerned in the execution of it. Adding to these considerations the natural diversity of human opinions on all new and complicated subjects, it is impossible to consider the degree of concord with ultimately prevailed as less than a miracle.”
James Madison letter to Thomas Jefferson, 24 October 1787 from The papers of James Madison, by William T. Hutchinson, William M.E. Rachal, and Robert A. Rutland, 10:207-8.