The Charcoal-Burner And The Fuller
There was once a Charcoal-burner who lived and worked by himself. A Fuller, however, happened to come and settle in the same neighbourhood; and the Charcoal-burner, having made his acquaintance and finding he was an agreeable sort of fellow, asked him if he would come and share his house: "We shall get to know one another better that way," he said, "and, beside, our household expenses will be diminished." The Fuller thanked him, but replied, "I couldn't think of it, sir: why, everything I take such pains to whiten would be blackened in no time by your charcoal."
The moral of the story:
People are driven apart by their differences more easily then they are brought together by what they have in common.