Evaluation of Frankfurt's Viewpoint in the Face of Indirect Consequence Argument

The different versions of van Inwagen’s indirect argument for the incompatibility of causal determinism and moral responsibility asserts that (1) the causal necessity and determination indicates that human actions are the results of past events and the laws of nature and thus does not have any alternative possibilities, while (2) every type of human free will and moral responsibility is based on such an alternative possibility to be capable of being chosen. Agreeing with the incompatibility of causal determination and the principle of alternative possibilities (PAP), Frankfurt tries to call the dependence of moral responsibility on the PAP into question. It seems, however, that the Frankfurt-style approach against the indirect argument suffers from being ambiguous in the status of the intervener. It is also incapable of explaining the significance and function of alternative possibility.