Contemporary theories of free will tend to fall into one of two general categories, namely, those that insist on and those that are skeptical about the reality of human freedom and moral responsibility. The former category includes libertarian and compatibilist accounts of free will, two general views that defend the reality of free will but disagree on its nature. The latter category includes a family of skeptical views that all take seriously the possibility that human beings do not have free will, and are therefore not morally responsible for their actions in a way that would make them truly deserving of blame and praise for them . The main dividing line between the two pro-free will positions, libertarianism and compatibilism, is best understood in terms of the traditional problem of free will and determinism. Determinism, as it is commonly understood, is roughly the thesis that every event or action, including human action, is the inevitable result of preceding events and actions and the laws of nature. The problem of free will and determinism therefore comes in trying to reconcile our intuitive sense of free will with the idea that our choices and actions may be causally determined by impersonal forces over which we have no ultimate control.