What magical ability does the monkey’s paw have?

Whether the monkey's paw possesses any magical powers at all is a big question which is never conclusively answered in the story. At the beginning of Part II, Mr. White makes a very significant statement.

"Morris said the things happened so naturally," said his father, "that you might if you so wished attribute it to coincidence."

Sergeant-Major Morris has had his three wishes, and the previous owner had three wishes. There are, according to Morris's story, only three more wishes left. Evidently the six wishes already made, and presumably granted, all could have been attributed to coincidence. When Mr. White receives two hundred pounds from Maw and Meggins as compensation for their son Herbert's accidental death at the factory, it could have been a mere coincidence that White had wished for that exact sum. 

Then when Mr. White wishes for his son Herbert to come back to life and return home, it could have been a coincidence that some stranger came knocking at the front door. And it could have been coincidental that the stranger stopped knocking and left right after Mr. White made his third and last wish, which was not included in the text but must have been that the knocking would cease and whoever was out there would go away. After all, if a stranger knocks at a door and nobody answers, he will go away. 

So the monkey's paw may have no magical ability at all. Common sense and reason tell us that there is no such thing as an object that has the power to grant wishes. It is just something we would like to believe. It makes a good story, like the story of "Aladdin and the Magic Lamp."

We do not know the nature of the three wishes made by the first owner of the monkey's paw, nor did Sergeant-Major Morris reveal anything about his own three wishes. If anybody had wished for something truly fantastic such as a fortune in gold or a palace full of servants, and had had the wish granted, then we could assume that the monkey's paw had magical powers. But the author deliberately avoids anything of the fantastic or supernatural. The story is about a very simple family living modestly in a house that is only worth about two hundred pounds. 

Another very intriguing story about an object that had the power to grant wishes is Robert Louis Stevenson's "The Bottle Imp." In that story the possessor of a certain magic bottle can have as many wishes as he wants. The only problem is that he has to sell it before he dies or he will go to hell for eternity. And the owner of the bottle always has to sell it for less than he paid for it. And over the years the selling price has been forced down until in the end the man who is stuck with the bottle is trying to dispose of this precious bottle for pennies. 

The appeal of all the many stories about a person being able to have his wishes granted is that they make us wonder what we would wish for if we knew our wishes would be granted. The common moral of many of these stories is usually the same:

Be careful about what you wish for, because your wish may be granted!