This is in response to an inquiry from a student.
This is where I have a lot of problems with Nash's presentation. I actually think that Nash's use of the term uninfluenced will makes some assumptions that I would be inclined to deny. Nash is a Calvinist, and I'm not a Calvinist, so we don't see eye to eye on free will.
Let's go back to that Adam and Eve story for a minute, to help illustrate the issue. Whether we take this story literally or not does not affect its value to illustrate a point. Suppose God were to place Adam and Eve in the Garden, but he didn't allow the serpent to get anywhere near the place. In fact, he created Adam in such a way that he always wanted to obey God. Given the state of Adam's desires, it really wouldn't matter whether that nasty serpent showed up or not. Adam and Eve wouldn't want to do anything that was disobedient toward God, and would simply tell that snake to go to hell if he suggested that to them that they disobey and eat from the Tree of the Knowledge of Good and Evil. The way Adam and Eve are put together, on this scenario, they cannot so much as desire to violate the law that God has laid down. Hence, they decline the invitation to sin, and get to remain in the garden forever. All the ills of human history, the wars, the plagues, the massacres, and all the sins, from the Holocaust down to me losing my temper yesterday, don't take place. Nobody goes to hell. God makes sure that Adam and Eve always want to do what is right, and he makes sure that he always has the opportunity to do what is right. In fact, God could not only have done this for Adam and Eve, he could have done this for Lucifer as well, in which case Lucifer would never have fallen.
If you talk to atheists, particularly those who have studied the free will problem, they will often tell you that that is precisely what God should have done. God could have created the world in such a way that everyone does what is right, and if God were a loving God, he would have done exactly that. Not only would we have avoided sinning, it turns out that one of the major philosophical definitions of what it is to have a free will is satisfied. "The liberty of spontaneity (the kind of free will a compatibilist thinks we have)...explains human freedom as the ability to do what the person wants to do." (Nash, p.328). Many people are taught to think that the reason why God permitted Adam and Eve to fall is because he had to give them free will in order to make it possible for them to be truly obedient, but in order to open that possibility, he also had to open the possibility that Adam and Eve disobey. But if God were to give Adam and Eve compatibilist free will, he could have allowed them to be free while at the same time guaranteeing that they would never sin. He didn't have to risk the fall of Adam and Eve, or the fall of Lucifer. So, if all we have is compatibilist free will, then we are going to need some other explanation for why God permitted Adam to sin. And theological Calvinists think that there is some other explanation. There are two explanations that I have heard. One is that God receives more glory if he predestines some people to disobey him, so that he can exercise his righteous wrath against unrepentant sin, as well as providing the saved a sense of what they were saved from. What is more, we can't be expected to understand why God does what he does, so even if those explanations don't wash (and they certainly don't for me), there is perhaps some unknown reason why God permitted (in fact, caused), the Fall of Man.
But, some people would ask whether this is real free will. If an outside agent, in the last analysis, is pulling the strings, can we be really said to have a free will? Some people have argued that we can't have real free will unless, given the past, we could have done otherwise from what we did. This is the incompatibilist, or libertarian, conception of free will. Nash refers to this as the uninfluenced will, but it is actually the libertarian conception of free will. It does not seem uninfluenced to me, on the contrary; it seems perfectly possible to be influenced by something that does not ultimately determine the will. Thus, I can be influenced by someone who wants me to marry Joan, but I might marry Susan instead, ultimately making a choice that could have gone the other way. I don't think it fair to describe an undetermined will as an uninfluenced will. Nash makes the argument that we always act on our strongest desire, but as the philosopher William Hasker has pointed out, "strongest" turns out to just mean "the desire we acted upon," in which case "we always act on our strongest desire" just turns out to mean "We always act on the desire we act on," which is hardly news to anyone. Many people in science, based on quantum mechanics, believe that some events occur even though sufficient causes for them have not taken place (though, or course, there have to be necessary conditions), yet they nevertheless occur.
This is a massive debate in philosophy, and I am just scratching the surface of it here.