Why does a married man call his wife as his "better half"?

Most married men believed that their wife is their "better half". Actually, the expression came from an old Middle Eastern story. The story is like this; once there was a Bedouin man who had been sentence to death. His wife was extremely crying and earnestly appealing to the tribal leader to free her husband.

She said that she and her husband became one when they were married. So, "to punish one-half of the union would also punish the half who was innocent", she said. The court agreed and the man's life was saved by his "better half".