“Franklin made only a few changes, some of which can be viewed written in his own hand on what Jefferson referred to as the ‘rough draft’ of the Declaration. (This remarkable document is at the Library of Congress and on its Web site.) The most important of his edits was small but resounding. He crossed out, using the heavy backslashes that he often employed, the last three words of Jefferson’s phrase ‘We hold these truths to be sacred and undeniable’ and changed them to the words now enshrined in history: ‘We hold these truths to be self-evident.’
The idea of ‘self-evident’ truths was one that drew less on John Locke, who was Jefferson’s favored philosopher, than on the scientific determinism espoused by Isaac Newton and on the analytic empiricism of Franklin’s close friend David Hume. In what became known as ‘Hume’s fork,’ the great Scottish philosopher, along with Leibniz and others, had developed a theory that distinguished between synthetic truths that describe matters of fact (such as ‘London is bigger than Philadelphia’) and analytic truths that are self-evident by virtue of reason and definition (‘The angles of a triangle equal 180 degrees’; ‘All bachelors are unmarried’). By using the word ‘sacred,’ Jefferson had asserted, intentionally or not, that the principle in question—the equality of men and their endowment by their creator with inalienable rights—was an assertion of religion. Franklin’s edit turned it instead into an assertion of rationality.”
From Benjamin Franklin: An American Life by Walter Isaacson.
In a later point in the book, Isaacson recounts a moment when, during the Constitutional Convention, the elder statesman Franklin established a metaphor for political compromise which our current Congress would do well to keep in mind:
Then he gently emphasized, in a homespun analogy that drew on his affection for craftsmen and construction, the importance of compromise: ‘When a broad table is to be made, and the edges of planks do not fit, the artist takes a little from both, and makes a good joint. In like manner here, both sides must part with some of their demands.’
Below: the rough draft of the Declaration