Many expositors claiming the name of Calvinism today hate the doctrine of God's unitary will. Great effort has been taken to find snippets of material from Calvin that harmonize with later Puritans, Spurgeon, and Dabney who taught a synthesis of paradoxical and conflicting wills in God. I am going to post a section of Book I, chapter XVIII from Calvin's Institutes that unquestionably make his doctrine clear on this matter. Calvin condemns in no uncertain terms the very arguments of low-grace Puritans and Fullerites who name themselves after him.
A very important distinction that Calvin enumerates is the difference between will and precept in scripture. The WILL of God (boulemai and thelo in the Greek) does not refer to the the COMMANDMENTS of God. God's will is his purpose, his passion, his lust, his determination to carry out all that he wishes. That is the meaning of the biblical usage. Yet most expositors today carelessly refer to the precepts of God and the will of God as equivalent entities.
Some will point out that there are those who are 'outside' of God's will according to statements of Christ in the synoptic gospels and a few other NT verses. It is important to understand the extreme difference between the concept of God's will involving a limited scope, as taught by certain NT scriptures, and the doctrine of paradoxical and conflicting wills of God. Gordon Clark in his Predestination has done an excellent job of explaining the synoptic use, which basically means God's KINGDOM WILL. Some miss God's passion in his kingdom purposes simply because they are not predestined to enter the kingdom. However, in no way does this mean that reprobates are outside of God's sovereign will in the broader sense-as testified to by many other passages of scripture.
The proposition being defended is that God has one unified purpose for all created things and his passions are never in conflict. In other words, God always gets everything he wants in the events of history and has no contrary passion. Here is Calvin:
Their first objection--that if nothing happens without the will of God, he must have two contrary wills, decreeing by a secret counsel what he has openly forbidden in his law--is easily disposed of. But before I reply to it, I would again remind my readers, that this cavil is directed not against me, but against the Holy Spirit, who certainly dictated this confession to that holy man Job, "The Lord gave, and the Lord has taken away," when, after being plundered by robbers, he acknowledges that their injustice and mischief was a just chastisement from God. And what says the Scripture elsewhere? The sons of Eli "hearkened not unto the voice of their father, because the Lord would slay them," (1 Sam. 2:25). Another prophet also exclaims, "Our God is in the heavens: he has done whatsoever he has pleased," (Ps. 115:3). I have already shown clearly enough that God is the author of all those things which, according to these objectors, happen only by his inactive permission. He testifies that he creates light and darkness, forms good and evil (Is. 45:7); that no evil happens which he has not done (Amos 3:6). Let them tell me whether God exercises his Judgments willingly or unwillingly. As Moses teaches that he who is accidentally killed by the blow of an axe, is delivered by God into the hand of him who smites him (Deut. 19:5), so the Gospel, by the mouth of Luke, declares, that Herod and Pontius Pilate conspired "to do whatsoever thy hand and thy counsel determined before to be done," (Acts 4:28). And, in truth, if Christ was not crucified by the will of God, where is our redemption? Still, however, the will of God is not at variance with itself. It undergoes no change. He makes no pretence of not willing what he wills, but while in himself the will is one and undivided, to us it appears manifold, because, from the feebleness of our intellect, we cannot comprehend how, though after a different manner, he wills and wills not the very same thing. Paul terms the calling of the Gentiles a hidden mystery, and shortly after adds, that therein was manifested the manifold wisdom of God (Eph. 3:10). Since, on account of the dullness of our sense, the wisdom of God seems manifold (or, as an old interpreter rendered it, multiform), are we, therefore, to dream of some variation in God, as if he either changed his counsel, or disagreed with himself? Nay, when we cannot comprehend how God can will that to be done which he forbids us to do, let us call to mind our imbecility, and remember that the light in which he dwells is not without cause termed inaccessible (1 Tim. 6:16), because shrouded in darkness. Hence, all pious and modest men will readily acquiesce in the sentiment of Augustine: "Man sometimes with a good will wishes something which God does not will, as when a good son wishes his father to live, while God wills him to die. Again, it may happen that man with a bad will wishes what God wills righteously, as when a bad son wishes his father to die, and God also wills it. The former wishes what God wills not, the latter wishes what God also wills. And yet the filial affection of the former is more consonant to the good will of God, though willing differently, than the unnatural affection of the latter, though willing the same thing; so much does approbation or condemnation depend on what it is befitting in man, and what in God to will, and to what end the will of each has respect. For the things which God rightly wills, he accomplishes by the evil wills of bad men,"--(August. Enchirid. ad Laurent. cap. 101). He had said a little before (cap. 100), that the apostate angels, by their revolt, and all the reprobate, as far as they themselves were concerned, did what God willed not; but, in regard to his omnipotence, it was impossible for them to do so: for, while they act against the will of God, his will is accomplished in them. Hence he exclaims, "Great is the work of God, exquisite in all he wills! so that, in a manner wondrous and ineffable, that is not done without his will which is done contrary to it, because it could not be done if he did not permit; nor does he permit it unwillingly, but willingly; nor would He who is good permit evil to be done, were he not omnipotent to bring good out of evil," (Augustin. in Ps. 111:2).
4. In the same way is solved, or rather spontaneously vanishes, another objection--viz. If God not only uses the agency of the wicked, but also governs their counsels and affections, he is the author of all their sins; and, therefore, men, in executing what God has decreed, are unjustly condemned, because they are obeying his will. Here will is improperly confounded with precept, though it is obvious, from innumerable examples, that there is the greatest difference between them.14When Absalom defiled his father's bed, though God was pleased thus to avenge the adultery of David, he did not therefore enjoin an abandoned son to commit incest, unless, perhaps, in respect of David, as David himself says of Shimei's curses. For, while he confesses that Shimei acts by the order of God, he by no means commends the obedience, as if that petulant dog had been yielding obedience to a divine command; but, recognising in his tongue the scourge of God, he submits patiently to be chastised. Thus we must hold, that while by means of the wicked God performs what he had secretly decreed, they are not excusable as if they were obeying his precept, which of set purpose they violate according to their lust.
How these things, which men do perversely, are of God, and are ruled by his secret providence, is strikingly shown in the election of King Jeroboam (1 Kings 12:20), in which the rashness and infatuation of the people are severely condemned for perverting the order sanctioned by God, and perfidiously revolting from the family of David. And yet we know it was God's will that Jeroboam should be anointed. Hence the apparent contradiction in the words of Hosea (Hosea 8:4; 13:11), because, while God complained that that kingdom was erected without his knowledge, and against his will, he elsewhere declares, that he had given King Jeroboam in his anger. How shall we reconcile the two things,--that Jeroboam's reign was not of God, and yet God appointed him king? In this way: The people could not revolt from the family of David without shaking off a yoke divinely imposed on them, and yet God himself was not deprived of the power of thus punishing the ingratitude of Solomon. We, therefore, see how God, while not willing treachery, with another view justly wills the revolt; and hence Jeroboam, by unexpectedly receiving the sacred unction, is urged to aspire to the kingdom. For this reason, the sacred history says, that God stirred up an enemy to deprive the son of Solomon of part of the kingdom (1 Kings 11:23). Let the reader diligently ponder both points: how, as it was the will of God that the people should be ruled by the hand of one king, their being rent into two parties was contrary to his will; and yet how this same will originated the revolt. For certainly, when Jeroboam, who had no such thought, is urged by the prophet verbally, and by the oil of unction, to hope for the kingdom, the thing was not done without the knowledge or against the will of God, who had expressly commanded it; and yet the rebellion of the people is justly condemned, because it was against the will of God that they revolted from the posterity of David. For this reason, it is afterwards added, that when Rehoboam haughtily spurned the prayers of the people, "the cause was from the Lord, that he might perform his saying, which the Lord spake by Ahijah," (I Kings 12:15). See how sacred unity was violated against the will of God, while, at the same time, with his will the ten tribes were alienated from the son of Solomon. To this might be added another similar example--viz. the murder of the sons of Ahab, and the extermination of his whole progeny by the consent, or rather the active agency, of the people. Jehu says truly "There shall fall unto the earth nothing of the word of the Lord, which the Lord spake concerning the house of Ahab: for the Lord has done that which he spake by his servant Elijah," (2 Kings 10:10). And yet, with good reason, he upbraids the citizens of Samaria for having lent their assistance. "Ye be righteous: behold, I conspired against my master, and slew him, but who slew all these?"
If I mistake not, I have already shown clearly how the same act at once betrays the guilt of man, and manifests the righteousness of God. Modest minds will always be satisfied with Augustine's answer, "Since the Father delivered up the Son, Christ his own body, and Judas his Master, how in such a case is God just, and man guilty, but just because in the one act which they did, the reasons for which they did it are different?" (August. Ep. 48, ad Vincentium). If any are not perfectly satisfied with this explanation--viz. that there is no concurrence between God and man, when by His righteous impulse man does what he ought not to do, let them give heed to what Augustine elsewhere observes: "Who can refrain from trembling at those Judgments when God does according to his pleasure even in the hearts of the wicked, at the same time rendering to them according to their deeds?" (De Grat. et lib. Arbit. ad Valent. c. 20). And certainly, in regard to the treachery of Judas, there is just as little ground to throw the blame of the crime upon God, because He was both pleased that his Son should be delivered up to death, and did deliver him, as to ascribe to Judas the praise of our redemption. Hence Augustine, in another place, truly observes, that when God makes his scrutiny, he looks not to what men could do, or to what they did, but to what they wished to do, thus taking account of their will and purpose. Those to whom this seems harsh had better consider how far their captiousness is entitled to any toleration, while, on the ground of its exceeding their capacity, they reject a matter which is clearly taught by Scripture, and complain of the enunciation of truths, which, if they were not useful to be known, God never would have ordered his prophets and apostles to teach. Our true wisdom is to embrace with meek docility, and without reservation, whatever the Holy Scriptures, have delivered. Those who indulge their petulance, a petulance manifestly directed against God, are undeserving of a longer refutation.