Solomon, in his Proverbs, has much to say about the wise and the fool, and also the children of wisdom and the children of folly. The children of wisdom are such as are made wise unto salvation through faith in our Lord Jesus Christ; but the children of folly embrace all natural and unregenerate men of Adam’s race, no matter how wise, learned, or intelligent they may be in natural things, or how ignorant they may be, they are all alikefools when brought in comparison or contrast with heavenly wisdom from above. "A wise man’s heart is at his right hand; but a fool’s heart is at his left."---Eccl. x. 2. It is thus shown that there is great contrast between the wise and the fool, and that no kind of pounding, beating, or bruising of the natural or unregenerate man with reproofs, rebukes, or arguments about religion, creeds, or gospel doctrine, will ever cause his foolishnessto depart from him. God turneth the wise men of this world backwards, upsets, and reverses all their plans and doctrines when any one of them is brought to the knowledge of the truth, and "maketh his knowledgefoolish." 

The figures used in the text heading this article, are very forcible. To bray, in the sense used in the text, is to beat, pound, bruise, or grind, as the ancient people did, and as people in new countries now do, when they beat or bruise their wheat or corn in a mortar with a pestle, in order to soften and prepare it for wholesome food. But should any spurious or poisonous grain be put in the same mortar among the wheat, no amount of pounding, or bruising would ever cause it to become wheat, but it would still retain its own natural poisonous character. And though it might increase the bulk of bruised grain, it would so corrupt or poison the quality as to render all unfit for wholesome use. 

Now, so far as the above remarks apply to natural things, they are easily understood, but how is it in spiritual things? One is a figure of the other. In Solomon’s description of a fool, he says, "It is an abomination to him to depart from evil."  He has no delight in understanding, and is always right in his own eyes, trusting in his own heart, so that there is no possibility of instructing him in spiritual things. This description is precisely in harmony with the words of Jesus that, "No man can come unto me, except my Father which hath sent me draw him, and I will raise him up at the last day."---John vi. 44.  It agrees also with Paul, that, "The natural man receiveth not the things of the Spirit of God; they are foolishness unto him, neither can he know them, because they are spiritually discerned."---1 Cor ii. 14. 

Now, to take this natural, unregenerate man as here described in these texts---this fool in scriptural things---and put him "among wheat," or among the children of wisdom in the church of God, and try to beat and pound the doctrine of grace into him by argument, admonition, reproof, or rebuke, so that he will delight in receiving and understanding it, is a task too great to ever be accomplished by all the pounding arguments that have ever been used by men or angels. He may be numbered with the brethren in the church, as Judas was numbered with the apostles, but after all this pounding, beating, and bruising, "his foolishness will not depart from him." 

It is true that the natural man, who receives not the things of the Spirit of God, may be taught and receive the letter of the written creed of the church, and he may learn the letter of the doctrine of Christ, so that he can make a strong argument from the letter of the written word, in favor of the doctrine of salvation by grace, and he may learn to prove by the written word of the Lord that there is a "remnant according to the election of grace," and that all the redeemed of the Lord are chosen in Christ before the foundation of the world that they may be holy and without blame before God in love, and he may be able to prove conclusively by the written word that all God’s people are predestinated to be conformed to the image of Jesus Christ, and he may further learn from the letter of the word something of the special and definite nature of the atonement are embraced therein save those who are chosen of God in Christ before the world began, and he may be so well posted in the written word that he can bring forth a scripture to sustain every leading principle of the gospel----and yet be but a natural man, who has never received, in his own experience, the things of the Spirit of God. He cannot know them till he is "born, not of blood, nor of the will of man, but of God." 

Now, if such a one described above should be numbered with the Lord’s people in the church, and happen to be a preacher, he may be learned and eloquent, bold and defiant in the letter of the truth, fond of argument, contention, and debate, but there is no amount of debating or pounding of him with the pestle of argument that will ever cause his foolish self-will and self-importance to depart from him. He knows only the letter and not the spirit of truth, and he feels but little concern how things go in the church. The prophet of God describes these characters in this way: "They lie upon beds of ivory, and stretch themselves upon the couches, and eat the lambs out of the flock and the calves out of the midst of the stall, they chant to the sound of the viol, and invent to themselves instruments of music, like David; drink wine in bowls and anoint themselves with the chief of ointments; but they are not grieved for the affliction of Joseph." Troubles in the church of God, and persecutions for righteousness sake, is no grief to them; "They are not in trouble as other men."---Psa. lxxiii. 

To one who knows only the letter and not the spirit of the gospel of Christ, strife, envy, and debate--disputation and contention about words, which subvert from the right way of the Lord--are to him mere playthings, idle fun and pastime, sporting with his own deceivings, even though it be to the great affliction and distress of real Christians. It is thus that such an one exemplifies the truth of the text, that braying or beating a fool in a mortar with a pestle among wheat, does not give him any new principle to make him partake of the wholesome flavor or quality of the wheat, nor will it cause his foolishness to depart from him; but like the poisonous grain that is bruised in the mortar among wheat, his carnal style and fleshly zeal will poison tile comforts and carnalize the minds of real Christians. A little, even a little, of this corrupting leaven will corrupt a whole church. 

Dear brethren, in view of the fact that the above is no fancy picture, and that preachers who only know the form and letter of truth, and not the spirit and power of it, and that they will engender a carnal spirit of envy and strife in and among the churches, would it not be well for churches to be careful as to whom they send forth to preach, and as to whom they receive? "Watch ye, stand fast in the faith, quit ye like men, be strong."--1 Cor. xvi. 13. With tears of sorrow Paul warns the churches against such preachers as serve not our Lord Jesus Christ, but serve their own greedy nature for earthly things, and by good words and fair speeches deceive the hearts of the simple.--Phil, iii. 19. It is the simple-hearted, unsuspecting Christian that is most likely to be caught in the net of fair speeches and beautiful outside influence and appearance.

In Psalm 14:1 we read, "The fool says in his heart, 'There is no God.'" That's a pretty blunt accusation - that a person who says there is no God, is a fool. Our modern overly-sensitive ears are startled when language like this is used. However, when the Bible speaks of"fools " and "foolishness" it isn't engaging in adolescent name calling. Instead, the word "fool " is used to describe a person who is in a state of moral and intellectual dullness. Greg Bahnsen cuts to the heart of the biblical teaching regarding foolsand foolishness. He writes: 

"If we are to understand how to answer the fool, if we are to be able to demonstrate that God has made the pseudo-wisdom of the world foolish, then we must first study the biblical conception of the fooland his foolishness. In scriptural perspective the fool is not basically a shallow-minded or illiterate ignoramus; he can be quite educated and sophisticated in social reckoning. However, he is a fool because he has forsaken the source of true wisdom in God in order to rely on his own (allegedly), self-sufficient, intellectual powers. He is unteachable (Prov. 10:8) and despises instruction (Prov. 15:5); whereas the wise man heeds council given to him, 'The way of a foolis right in his own eyes' (Prov. 12:15). Thefool has utter self-confidence and imagines himself to be intellectually autonomous. 'He that trusteth in his own heart is a fool ' (Prov. 28:26). A fool cannot think of himself as mistaken (Prov. 17:10). He judges matters according to his own pre-established standards of truth and right, and thus his own thoughts always turn out in the long run to be correct. The fool is sure that he can rely on his own rational authority and intellectual scrutiny. 'The fool beareth himself insolently and is confident' (Prov. 14:16), and therefore he utters his own mind (Prov. 29:11). In actuality, this autonomous man is dull, stubborn, boorish, obstinate and stupid. He professes himself to be wise, but from the opening of his mouth it is clear that he is (in the biblical sense) 'a fool ' - his only wisdom would consist in keeping silent (Prov. 17:28). 'The heart of fools proclaimeth foolishness ' (Prov. 12:23), and the foolflaunts his folly (Prov. 13:16). He eats up folly unreflectingly (Prov. 15:14), pours it out (Prov. 15:2), and returns to it like a dog to his vomit (Prov. 26:11). He is so in love with his folly and so dedicated to its preservation that 'It is better for a man to meet a bear robbed of her whelps, than afool is his folly' (Prov. 17:12). The fooldoes not want to find the truth; he only wants to be self-justified in his own imaginations. While he may feign objectivity, 'Afool hath no delight in understanding, but only that his heart may reveal itself' (Prov. 18:2). He is committed to his own presuppositions and wishes to guard his autonomy. Thus he will not depart from evil (Prov. 13:19), and thus all his knowledgeable talk reveals nothing but perverse and lying lips (Prov. 10:18; 19:1). He may talk proudly, but "A fool's mouth is his destruction, and his lips are a snare of his soul' (Prov. 18:7). He shall not endure the judgment of God (Ps. 5:5)." (Greg Bahnsen, Always Ready, pp. 55-56) 

"Do not answer a fool according to his folly, or you will be like him yourself." 

What the world calls 'foolish' is in reality wisdom. Conversely, what the world deems 'wise' in actuallyfoolish. The unbeliever has his standards all turned around, and thus he mocks the Christian faith or views it as intellectually dishonorable. (Bahnsen, p. 59) 

However, Proverbs 26:5 (the very next verse) says, 

"Answer a fool according to his folly, or he will be wise in his own eyes." 

I cannot summarize this two-fold apologetic procedure any better than Greg Bahnsen. He writes, 

In the first place, the unbeliever should not be answered in terms of his own misguided presuppositions; the apologist should defend his faith by working within his own presuppositions. …But then in the second place the apologist should answer the fool according to his self-proclaimed presuppositions (i.e., according to his folly). In so doing he aims to show the unbeliever the outcome of those assumptions. Pursued to their consistent end presuppositions of unbelief render man's reasoning vacuous and his experience unintelligible; in short, they lead to the destruction of knowledge, the dead-end of epistemological futility, to utter foolishness. (Bahnsen 61-62)