John Chadwick quotes:

Of the six men who have done most to make America the wonder and the joy she is to all of us, not one could be the citizen of a government so constituted; for Washington and Franklin and Jefferson, certainly the three mightiest leaders in our early history, were heretics in their day, Deists, as men called them; and Garrison and Lincoln and Sumner, certainly the three mightiest in these later times, would all be disfranchised by the proposed amendment. Lincoln could not have taken the oath of office had such a clause been in the Constitution.

This method of deduction ... is often called "combinatory". Its usefulness is not exhausted at this stage, but it does even at the outset lead to some valuable conclusions.

It is this quality, the power of seeing order in apparent confusion, that has marked the work of all great men.