When the Declaration of Independence was still a draft, Benjamin Franklin, sitting beside Thomas Jefferson, revised Jefferson's wording of "We hold these truths to be sacred and undeniable" to the now-famous phrase, "We hold these truths to be self-evident." According to biographer Walter Isaacson, Jefferson was distraught by Franklin's edits. So Franklin, aware of his friend's state, sought to console Jefferson by telling him the tale of his friend John Thompson.
John had just started out in the hat-making business and wanted a sign for his shop. He composed his sign like so:
Before using the new sign, John decided to show it to some friends to seek their feedback. The first friend thought that the word "hatter" was repetitive and unnecessary because it was followed by the words "makes . . . hats," which showed that John was a hatter. The word "hatter" was struck out. The next friend observed that the word "makes" could be removed because his customers would not care who made the hats. So "makes" was struck out. A third friend said he thought the words "for ready money" were useless, as it was not the custom to sell hats on credit. People were expected to purchase hats with money. So those words were omitted.
The sign now read, "John Thompson sells hats."
"Sells hats!" said his next friend. "Why, nobody will expect you to give them away. What then is the use of that word?" "Sells" was stricken. At this point there was no use for the word "hats" since a picture of one was painted on the sign. So the sign was ultimately reduced to:
In his book Simple and Direct, Jacques Barzun explains that all good writing is based upon revision [Barzun, 227]. Revision, he points out, means to re-see. John Thompson's sign was gradually revised by his friends, who helped him remove duplicate words, simplify his language, and clarify his intent. Jefferson's words were revised by Franklin, who saw a simpler, better way to express Jefferson's intent. In both cases, having many eyes revise one individual's work helped produce dramatic improvements.
The same is true of code. To get the best refactoring results, you'll want the help of many eyes. This is one reason why extreme programming suggests the practices of pair-programming and collective code ownership [Beck, XP].