“So far as my observation extends, those persons who affect to treat this distinction as a matter of mere curious speculation, are as ready to make use of it as other people 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 it be of this kind or that:’ but labours with all his might to establish the difference. Now if the subject be so clearly understood and acted upon where interest is concerned, and never appears difficult but in religion, it is but too manifest where the difficulty lies. If by fixing the guilt of our conduct upon our father Adam, we can sit comfortably in our nest; we shall be very averse to a sentiment that tends to disturb our repose, by planting a thorn in it.
“It is sometimes objected, that the inability of sinners to believe in Christ, is not the effect of their depravity; for that Adam himself in his purest state was only a _natural man_, and had no power to perform spiritual duties. But this objection belongs to another topic, and has, I hope, been already answered. To this, however, it may be added—_The natural man who receiveth not the things of the Spirit of God_, (1 Cor. ii. 14.) is not a man possessed of the holy image of God, as was Adam, but of mere natural accomplishments; as were the _wise men of the world_, the philosophers of Greece and Rome, to whom the things of God were _foolishness_. Moreover, if the inability of sinners to perform spiritual duties, were of the kind alleged in the objection, they must be equally unable to commit the opposite sins. 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 hearts renders them incapable of the former.