Other Posts in This Series: Part 1; Part 3; Whole Paper.
It will be helpful, prior to addressing further differences with Dr. Nettles, to establish what Andrew Fuller means by his distinction between natural and moral inability. Speaking of himself in the third person, in the preface of Gospel Worthy, Fuller explains that he was introduced to the difference between natural and moral inability by studying Jonathan Edwards:
He had also read and considered, as well as he was able, President Edwards’s Inquiry into the Freedom of the Will, with some other performances on the difference between natural and moral inability. He found much satisfaction in this distinction; as it appeared to him to carry with it its own evidence—to be clearly and fully contained in the Scriptures—and calculated to disburden the Calvinistic system of a number of calumnies with which its enemies have loaded it, as well as to afford clear and honourable conceptions of the Divine government.
Fuller’s adoption of this distinction does not establish that he adopted the theology (and philosophical baggage) of Edwards in toto. It would beg the question if one were to argue, that because the meaning of Edwards carries a certain nuance and philosophical bent, then Fuller’s meaning must carry the same. To understand Fuller, we must look to Fuller and how he understood this distinction.
The main difference between moral inability and natural inability, to Fuller, was that in natural inability, one is unable no matter how much one might be willing; whereas, moral inability consists only in one’s unwillingness due to “an evil bias of heart.” Natural inability is “the want of natural powers and advantages,” while moral inability is merely “the want of a heart to make a right use of them.” Fuller, arguing the duty of faith and the implicit ability of sinners to believe, stated:
If faith were no more a duty than election or redemption, which are acts peculiar to God, the want of the one would be no more ascribed to the evil dispositions of the heart than that of the other. Or, if the inability of sinners to believe in Christ were of the same nature as that of a dead body in a grave to rise up and walk, it were absurd to suppose that they would on this account fall under the Divine censure. No man is reproved for not doing that which is naturally impossible; but sinners are reproved for not believing, and given to understand that it is solely owing to their criminal ignorance, pride, dishonesty of heart, and aversion from God.
Fuller states, “It is common, both in Scripture and in conversation, to speak of a person who is under the influence of an evil bias of heart, as unable to do that which is inconsistent with it.” Fuller points to Joseph’s brothers, in Gen. 37:4 , who “could not speak peaceably” to Joseph, as an example of an expression of moral inability. Who would think from reading this verse that Joseph’s brothers were unable to speak peaceably to him no matter how much they might want to? Everyone immediately comprehends that their inability was not the kind that provides an excuse. It is universally understood that when it comes to terms of inability, such as cannot, could not, and unable, the context determines whether they are meant in the literal, natural sense of being absolutely unable, or meant in the figurative, moral sense of being unable only from lack of desire.
Fuller also explains, “If sinners were naturally and absolutely unable to believe in Christ, they would be equally unable to disbelieve; for it requires the same powers to reject as to embrace.” Fuller states:
He that, from the constitution of his nature, is absolutely unable to understand, or believe, or love a certain kind of truth, must, of necessity, be alike unable to shut his eyes against it, to disbelieve, to reject, or to hate it. But it is manifest that all men are capable of the latter; it must therefore follow that nothing but the depravity of their heart renders them incapable of the former.
For Fuller, natural inability is an absolute lack of ability, which gives one an absolute lack of accountability. As Fuller stated above, “[...] it were absurd to suppose that they [whose inability... were of the same nature as that of a dead body... to rise up and walk] would on this account fall under Divine censure.” Fuller explains:
[...] Some men pass through life totally insane. This may be one of the effects of sin; yet the Scriptures never convey any idea of such persons being dealt with, at the last judgment, on the same ground as if they had been sane. On the contrary, they teach that “to whom much is given, of him much shall be required.” Another is deprived of the sight of his eyes, and so rendered unable to read the Scriptures. This also may be the effect of sin; and, in some cases, of his own personal misconduct; but whatever punishment may be inflicted on him for such misconduct, he is not blameworthy for not reading the Scriptures after he has lost his ability to do so. A third possesses the use of reason, and of all his senses and members; but has no other opportunity of knowing the will of God than what is afforded him by the light of nature. It would be equally repugnant to Scripture and reason to suppose that this man will be judged by the same rule as others who have lived under the light of revelation. “As many as have sinned without law shall also perish without law; and as many as have sinned in the law shall be judged by the law.” The inability, in each of these cases, is natural; and to whatever degree it exists, let it arise from what cause it may, it excuses its subject of blame, in the account of both God and man. The law of God itself requires no creature to love him, or obey him, beyond his “strength,” or with more than all the powers which he possesses.
Yet, sinners remain accountable in spite of their moral inability. Fuller goes on to state, “There is an essential difference between an ability which is independent of the inclination, and one that is owing to nothing else.” He describes this moral inability “that is owing to nothing else” (than inclination) as “aversion of heart:” “They will not come to Christ that they may have life; will not hearken to the voice of the charmer, charm he never so wisely; will not seek after God; and desire not the knowledge of his ways.” It is inability used in its improper or figurative sense, and not in its proper, literal sense, because being morally unable does not leave one absolutely unable. Fuller explains in his “Reply to Philanthropos:”
[...] when the terms cannot, inability, &c. are used in these connexions, they are used not in a proper, but in a figurative sense; that they do not express the state of a person hindered by something extraneous to his own will, but denote what we usually mean by the phrase cannot find in his heart; [...]
Fuller affirms that “the whole of our meaning” is that moral inability is unwillingness (and that there is a certainty to that unwillingness), in his reply to Dan Taylor:
But Mr. T. contends that “there is no goodness, no mercy, no tender mercy, exercised towards a person who is placed in such a situation that he could not avoid sinning and being damned, and whose damnation is necessarily increased by calls and commands to repent, and believe in Christ; when the great God, whose commands these are, has provided no mercy for him, nor intends to give him the least assistance, though he knows the poor sinner cannot, nor ever possibly could, obey these calls and commands, any more than he can fly to the moon,”—XIII. 106. To this shocking representation I have only to say, This is not my hypothesis, nor any thing like it; [...] The whole passage is mere declamation, founded on the abuse of the terms cannot, could not, &c. If, instead of “cannot, and never could,” he had said will not, and never would, his account of the poor sinner’s case would not have appeared so plausible; and yet this he knows is the whole of our meaning.
In “Answers to Queries,” Fuller rebuts the claim that moral inability is absolute inability, and affirms that the sinner’s “ability to comply” is “in the power of his hand:”
[...] I believe the heart of man to be by nature the direct opposite of honest. I am not aware, however, that I have any where represented an honest heart as constituting our ability to comply with gospel invitations, unless as the term is sometimes used in a figurative sense, for moral ability. I have said, “There is no ability wanting for this purpose in any man who possesses an honest heart.” If a person owed you one hundred pounds, and could find plenty of money for his own purposes, though none for you; and should he at the same time plead inability, you would answer, there was no ability wanting, but an honest heart: yet it would be an unjust construction of your words, if an advocate for this dishonest man were to allege that you had represented an honest heart as that which constituted the ability to pay the debt. No, you would reply, his ability, strictly speaking, consists in its being in the power of his hand, and this he has. That which is wanting is an honest principle; and it is the former, not the latter, which renders him accountable. It is similar with regard to God. Men have the same natural powers to love Christ as to hate him, to believe as to disbelieve; and this it is which constitutes their accountableness. [...]
[...] If I be under no other inability than that which arises from a dishonesty of heart, it is an abuse of language to introduce the terms “possible, impossible,” &c., for the purposes of diminishing the goodness of God, or destroying the accountableness of man. I am not wanting in power provided I were willing; and if I be not willing, there lies my fault. [...]
Answering those who would deny the significance of the distinction between moral and natural inability, Fuller explains:
“If we be unable,” say they, “we are unable. As to the nature of the inability, it is a matter of no account. Such distinctions are perplexing to plain Christians, and beyond their capacity.”—But surely the plainest and weakest Christian, in reading his Bible, if he pay any regard to what he reads, must perceive a manifest difference between the blindness of Bartimeus, who was ardently desirous that “he might receive his sight,” and that of the unbelieving Jews, who “closed their eyes, lest they should see, and be converted, and be healed;” and between the want of the natural sense of hearing, and the state of those who “have ears, but hear not.”
Masterfully, Fuller turns the tables and charges those who deny the significance of the distinction with being ready to make use of it “where their own interest is concerned:”
If they be accused of injuring their fellow creatures, and can allege that what they did was not knowingly, or of design, I believe they never fail to do so; or, when charged with neglecting their duty to a parent or a master, if they can say in truth, that they were unable to do it at the time, let their will have been ever so good, they are never known to omit the plea; and should such a master or parent reply, by suggesting that their want of ability arose from want of inclination, they would very easily understand it to be the language of reproach, and be very earnest to maintain the contrary. You never hear a person in such circumstances reason as he does in religion. He does not say, “If I be unable I am unable; it is of no account whether my inability be of this kind or that:” but he labours with all his might to establish the difference.
Answering those who contend that the inability of sinners is of both kinds, Fuller argues that moral inability presupposes a natural ability, and a natural inability precludes a moral one:
Some writers [...] have allowed that sinners are the subjects of an inability which arises from their depravity; but they still contend that this is not all, but that they are both naturally and morally unable to believe in Christ; and this they think agreeable to the Scriptures, which represent them, as both unable and unwilling to come to him for life. But these two kinds of inability cannot consist with each other, so as both to exist in the same subject and towards the same thing. A moral inability supposes a natural ability. He who never, in any state, was possessed of the power of seeing, cannot be said to shut his eyes against the light. If the Jews had not been possessed of natural powers equal to the knowledge of Christ’s doctrine, there had been no justice in that cutting question and answer, “Why do ye not understand my speech? Because ye cannot hear my word.” A total physical inability must, of necessity, supersede a moral one. To suppose, therefore, that the phrase, “No man can come to me,” is meant to describe the former; and, “Ye will not come to me that ye may have life,” the latter; is to suppose that our Saviour taught what is self-contradictory.
Fuller expands on this:
[...] some writers have affirmed that men are under both a moral and a natural inability of coming to Christ, or that they neither will nor can come to him: but if there be no other inability than what arises from aversion, this language is not accurate; for it conveys the idea, that if all aversion of heart were removed, there would still be a natural and insurmountable bar in the way. But no such idea as this is conveyed by our Lord’s words: the only bar to which he refers lies in that reluctance or aversion which the drawing of the Father implies and removes. Nor will such an idea comport with what he elsewhere teaches. “And because I tell you the truth, ye believe me not. Which of you convinceth me of sin? And if I say the truth, why do ye not believe me? He that is of God heareth God’s words: ye therefore hear them not, because ye cannot hear my word.” These cutting interrogations proceed on the supposition that they could have received the doctrine of Christ, if it had been agreeable to their corrupt hearts; and its being otherwise was the ONLY reason why they could not understand and believe it.
Those whose vision is polarized and who see the issue only as ‘determinative versus nondeterminative’ tend to view the prospect of moral inability as if that inability was absolute just as natural inability is absolute. However, this is to conflate the two, as if the moral use of the terms of inability were just as proper and literal as the natural use of those terms. Again, replying to Taylor, Fuller affirms the figurative use of the terms of inability and further, draws out the connection to the issue of certainty as opposed to necessity:
[...] “If,” says he [Mr. T.], “any such election be maintained as supposes that all the rest of mankind never enjoyed the possibility of happiness, nor had any provision of happiness made for them, but were necessarily, either from eternity or from their birth, exposed to eternal misery, such election as this I deliberately consider as opposite to the spirit and design of the gospel, and to the tenor of Scripture,”—XIII. 100. To this it is replied, All such terms as necessary, cannot, impossible, &c., when applied to these subjects, are used improperly. They always denote, in strict propriety of speech, an obstruction arising from something distinct from the state of the will. Such terms, in their common acceptation, suppose a willingness in us to perform an action, or obtain an end, but that we are hindered by some insurmountable bar from without. Such an idea is always annexed to the use of such terms; and Mr. T. certainly has this idea in his use of the terms necessary and impossible, in this place. His meaning is to oppose that doctrine which represents a part of mankind as placed in such circumstances, as that, though they should be willing to embrace him, yet it would be all in vain. But such a doctrine nobody maintains; at least, I had no such ideas of the subject. I have no such notion of election, or of the limited extent of Christ’s death, as that it shall be in vain for any of the sons of men truly to seek after God. If they are willing to be saved in God’s way, nothing shall hinder their salvation; and (if there were any meaning in the expression) if they were but truly willing to use means that they might be willing, all would be clear before them.
Having denied the necessity and the absolute inability, Fuller, continuing, goes on to address the certainty:
Now, where this is the case, it cannot be said, in strict propriety of speech, that no provision is made for their happiness, or that any man’s salvation is impossible, or his destruction necessary; seeing the way of salvation is open to him, if he will but walk in it. All that can be said in truth is that there is a CERTAINTY in these things. It is certain that none will be saved but those who choose to be saved in God’s way. It is certain that no one will choose that which is opposite to the prevailing bias of his heart. Yea, it is certain that, whatever means there may be adapted to the turning of his heart, a man who is wholly averse from God will never make use of them with such a design.
Fuller clearly and explicitly affirmed—and with the emphasis of all capital letters—that the moral inability of sinners puts them (apart from God’s grace) under a “CERTAINTY” of rejecting Christ and not a necessity. Moral bias of heart does not leave men absolutely unable, but only results in the certainty that they will not use the natural ability that they have to believe and come to Christ (apart from the persuasions of God’s grace).
Ken Hamrick, 2014
 Andrew Fuller, “The Gospel Worthy of All Acceptation,” The Complete Works of Andrew Fuller, (Harrisonburg: Sprinkle, 1988), vol. II, p. 330.
 Ibid., p. 331.
 Ibid., pp. 354-355.
 Ibid., p. 356.
 Ibid., p. 377.
 Ibid., p. 357.
 Ibid., p. 378.
 Ibid., p. 376.
 Ibid., p. 330.
 “Reply to Philanthropos,” Complete Works, vol. II., p. 476.
 ” Reality and Efficacy,” Letter XII, p. 551.
 “Answers to Queries,” Complete Works, vol. III., pp. 768, 769.
 “Gospel Worthy,” p. 377.
 Ibid., p. 378.
 Ibid., pp. 356-357.
 “Reality and Efficacy,” Letter X, pp. 545-546.