In Macbeth, a classic tragedy, Shakespeare addresses the question of free will. Macbeth, a Scottish lord meets three witches after winning a battle. They call him "Thane of Cawdor" and "future King of Scotland" before this even happens. But King Duncan, though rewarding him with the title of the recently executed Thane of Cawdor, announces that his son will be heir to the throne. Macbeth believes that he has to kill the king now to fulfill the prophecy of the witches. Once Macbeth becomes king, however, he becomes so paranoid about losing power that he starts killing everyone around him, Kissinger style. Eventually his friends turn on him, and then even his army.
Macbeth follows the advice of the three witches after seeing them again and they conjure the dead to guide him (with tragic results). There is a paradox in this play where the witches know about Macbeth being the future king, but we do not know if he would have even thought about being king if he had not met them.
Interestingly, there is a modern parallel in this very presidential election in terms of the conjuring of "Eleanor" while Secretary of State...
Now in Peru, Hillary, did Eleanor say you would be president? Or was it some other time?
“And a special thanks to the members of the Roosevelt family who are here, and the one who is not, Eleanor…Because as all of you famously learned when I served as president, my wife, now the Secretary of State, was known to commune with Eleanor on a regular basis…she told me that Eleanor reminded her to tell me that I should say that…”Bill Clinton (see video clip above) See source from Trey Smith