So far, I have argued (1) that the Bible does not teach libertarian freedom, and (2) that libertarian freedom is not necessary for moral responsibility.
I turn finally to the third reason to reject libertarianism: it can be shown that not only is libertarianism unnecessary for moral responsibility, it is positively inconsistent with moral responsibility. That is, if a person has free will such that his actions are indetermined, he cannot be morally responsible for his actions. Let me give you an argument to show you why.
Suppose there is a person named Smith, who is trying to decide between two job offers. Let us label the first job "JobA" and the second job "JobB." And let us suppose that there are reasons in favor of Smith choosing JobA, and other reasons in favor of Smith choosing JobB. The former we will call RA and the latter RB. Now RA may include such factors as that the salary is higher than that of JobB, the location is in a low-crime area, and so on. But, other equally significant factors support JobB, so that RB includes the fact that the location is closer to family, the work is easier, and so on. Now suppose that Smith finally decides to accept the offer for JobA. We need to ask the question, then, "Why did Smith choose JobA?" The libertarian, being an indeterminist, cannot say that the reasons Smith had for JobA—RA—compelled or determined that Smith choose that job. Smith, being free, could have done otherwise. But, I want to suggest that if Smith had free will when he choose JobA, then his actions were random and arbitrary in such a way that he could not possibly be morally responsible for choosing JobA.
The libertarian, of course, will cry foul at this point. "How can Smith’s choice be arbitrary since he had some reasons—RA—for choosing it?" Well, I can agree that RA can be meaningfully cited as reasons for why Smith chose JobA, but I submit that the libertarian has answered the wrong question. The salient question is not, "Why did Smith choose JobA?", but "Why did Smith choose JobA rather than JobB?" I do not think that the libertarian can answer this question satisfactorily.
In fact, I believe that the libertarian indeterminist is caught on the horns of a dilemma: The question is, "Why did Smith choose JobA rather than JobB?" Either there is an answer to this question or there is not. If there is an answer, then Smith's choice is determined (and indeterminism is false). If there is no answer, then Smith's choice is made arbitrarily. So, if indeterminism is true, then Smith's choice is a random choice, and his moral responsibility for that choice is vitiated. Let me present this dilemma a bit more formally:
(1) Either there is a causally sufficient reason why Smith chose JobA rather than JobB, or there is not.
(2) If there is a causally sufficient reason why, then Smith's choice is determined.
(3) If there is no causally sufficient reason why, then Smith's choice is arbitrary.
In defense of (3), let us imagine three different scenarios regarding the relative weight of the reasons Smith may have with respect to the two job offers. First, suppose that Smith's reasons for choosing either job are equally weighted. That is, let it be the case that RA provides no motivation to prefer JobA to JobB, and vice versa. If so, then it seems that there is no reason why Smith chose JobA rather than JobB, even though he did have the considerations of RA in favor of JobA. Would not his choice to accept one job rather than the other be just as arbitrary as if he had no reasons for choosing either job (i.e., if both RA and RB did not exist)? So it seems. So, how does adding equally weighted reasons for the respective jobs diminish the arbitrariness of the choice in such a way as to ground Smith's moral responsibility?
The difficulty does not go away if we assume that RA and RB are not equally weighted. Suppose that RA makes the choice of JobA more preferable, so preferable in fact that it would be clearly irrational to choose JobB. The indeterminist/libertarian would still maintain that there is no causally sufficient reason why Smith chooses JobA (if in fact he does choose JobA). Smith is perfectly capable of choosing JobB in this situation. But, the compatibilist can reply that moral responsibility would come down, on this view, to having the ability to make an irrational choice. And who would want such an ability?
But, what if RA is weightier than RB, but not by a great margin? That is, would our assessment of Smith's moral responsibility be any different if he had some reason to prefer JobA to JobB, yet that reason was not so overwhelmingly preferable that choosing JobB instead would seem obviously crazy? I don't think so. It would still turn out to be irrational to choose JobB if Smith could not say anything in explanation of his choice.
To see this, imagine two possible worlds, W1 and W2, that both contain our character Smith. And let us assume that in both worlds he has some small preference for JobA as opposed to JobB (but not a very strong preference). Now suppose also that in both worlds Smith opts for JobB (the less preferable job). Intuitively, is seems possible for such a choice to be made, and we would not, in ordinary situations, immediately charge someone who made such a choice with irrationality. Let us suppose, for example, that in W1 Smith, if asked why he chose JobB rather than JobA, would reply, "I just had a gut feeling about JobB." We would be prone, I think, to accept this answer and not consider Smith irrational because acting on a gut feeling is often the appropriate thing to do and does in fact constitute a reason for Smith to really prefer JobB after all. It's the presence of this reason that explains why we are willing to give Smith's rationality (in W1) the benefit of the doubt.
However, suppose that things are slightly different with respect to Smith in W2. Suppose that he had no gut feelings about JobB that influenced him to choose it in spite of JobA's apparent preferability. We ask, "So even though JobA seemed more preferable on purely rational grounds, you chose JobB because it appealed to you in some unspecifiable way?" Smith replies, "No, JobA appealed to me more. I just picked JobB. No reason." It would be safe to conclude that Smith is irrational. He quite arbitrarily chose JobB rather than JobA against clear reasons for the latter, and he did so for absolutely no reason. Hence, it would seem that the indeterminist wants us to ground responsibility in the ability to act irrationally. But, I submit that there is no reason that we should go along with this. When people act irrationally and arbitrarily, we tend to think that they are defective in some way—in a way that causes us to mitigate their moral responsibility. So, it would seem that libertarian free will is actually inconsistent with moral responsibility.
What do I conclude from all this? When confronted with the apparent problem of reconciling God’s sovereignty and free will, there is no reason to follow the Arminian in opting for free will and rejecting divine sovereignty, nor is there any need to paradoxically hold these concepts in tension. Because the only motivation for holding on to free will—the need to preserve moral responsibility—has no force. Moral responsibility does not require free will, and thus there is no reason, no motive, to diminish God’s sovereignty.