Add to ORKGThe focus of this dissertation is the principle of alternate possibilities (PAP), a fundamental principle of much libertarian or incompatibilist theory on the perennial problem of reconciling freedom and determinism. The essence of this principle has been employed in some form by various thinkers since at least the time of the Stoics, but I borrow the term from Harry Frankfurt, who named the principle in his seminal article, Alternate Possibilities and Moral Responsibility\u27\u27 (Frankfurt, 1969). Since it would be a quite daunting task to follow the use of this principle throughout its history, I will limit myself for the most part to how it has figured in the contemporary debate following Frankfurt\u27s article..