As the man drew closer Sam realized that they looked very similar. In fact, the man was an exact double of Sam.
When his double came within walking distance of Sam he spoke, telling Sam that he would die in one year's time. After delivering this dire warning the double vanished.
A year passed. Sam had been invited to a barn-raising, and although it was the day of his alleged doom he went anyway. Barn-raisings were important social events for rural communities, and Sam didn't want to miss the chance to visit with his neighbors. Besides, he didn't really believe his double's warning anyway.
Sam had told everyone in Cavendish about his double's warning shortly after it had been delivered, so all his neighbors knew this was the day that Sam might die. When he arrived at the work site they refused to let him participate. "Too dangerous," they said, "but you can sit and watch."
Sam sat and watched, but when his neighbors went into the house to eat he decided to climbed up on the scaffolding to adjust the work someone else had done. As he stepped back to admire his adjustment he fell off the platform onto the hard ground below. He died instantly. The double's warning had come true.
This story first appeared in 1901 magazine called Scribbler, and the author starts it by writing "But never since the world began has it been told that a man met his own ghost." That's some nice hyperbole, but it's simply not true. In fact a similar story was told in Massachusetts just a few years earlier.
Clifton Johnson includes the following in his book What They Say in New England (1896). A wealthy man come home one winter day to find his wife in tears. When he asked why she said that she had looked out the window and seen herself walking in the snow. She knew this meant she would die soon. Within a year she passed away. As Clifton Johnson ends the story he notes that Abraham Lincoln saw his double shortly before he was assassinated. The idea that seeing your double means death was apparently well known.
|Dante Gabriel Rossetti, How They Met Themselves, 1864|
The concept can actually be traced back to old European folk beliefs and can be found in stories from the Middle Ages and in Viking sagas. The Germans have a specific word for this phenomenon, doppelganger, which literally means "double goer." I've also seen the word double goer used in English accounts of doubles.
One of the core beliefs in old European folklore is that everyone has a soul that looks identical to your physical body. This belief explains a lot of other odd things: that witches can send out their souls to torment people, that vampires have no reflection (because they have no soul), that breaking a mirror is bad luck (because you're damaging your double), and that babies shouldn't look at mirror before baptism (because their souls are not fully attached and will be stuck in the mirror).
Occasionally a person's soul appears to deliver a warning, usually of impending doom. It's the soul's way of saying, "Hey, it's been nice, but we aren't going to be together very much longer." That's what's happening in the stories about Sam Connor and the others.
If you encounter your double you could try running the other way, but it probably wouldn't help. The doppelganger isn't really the problem, it's just telling you what's going to happen. Maybe you should just say thank you and put your affairs in order?
The best book on this topic is Claude Lecouteux's Witches, Werewolves and Fairies: Shapeshifters and Astral Doubles in the Middle Ages (2003). It focuses mostly on European material but is fascinating nonetheless.