Stapleton's third argument is that Scripture cannot be proved from Scripture; therefore, we need the Magisterium to identify Scripture for us. He explains this in more detail, using an example I've seen in various forms online discussion boards over the years:
Should any one, [Stapleton] says, deny Paul's epistles to be canonical, it cannot be proved either from the old Testament, or from the gospel, because there is nowhere any mention there made of them. Then he goes on to say that neither the whole scripture, nor any part of it, can be proved from scripture itself, because all proof is drawn from things better known than the thing to be proved. Therefore (says he) to one who denies or knows not either the whole scripture or any part of it, nothing can be proved from scripture itself. But here, according to him, the church comes to our help in both cases. For, should any one deny a part of scripture, the church persuades him to receive these books upon the same ground as he hath received the others: he who is ignorant of the whole scripture, it persuades to accept the scripture in the same way as he hath accepted Christ.1
Whitaker's response contains too much material to effectively summarize all of it, so it seemed best to draw out just a few relevant points--that we can recognize Scripture as God's voice through the internal testimony of the Holy Spirit and that there are external testimonies available to prove the canon as well (although to a lesser, different degree than the certainty provided by the Holy Spirit).
Scripture as the Recognizable Voice of God
Whitaker describes Scripture as recognizable, as one voice is recognizable from another or from other sounds:
From these2 and similar passages, we reason thus: There is the greatest perspicuity and light in the scriptures: therefore the scripture may be understood by the scripture, if one only have eyes to perceive this light. As the brightest light appears in the sun, so the greatest splendour of divinity shines forth in the word of God. The blind cannot perceive even the light of the sun; nor can they distinguish the splendour of the scriptures, whose minds are not illuminated. But those who have eyes of faith can behold this light. Besides, if we recognize men when they speak, why should we not also hear and recognise God speaking in his word? For what need is there that another should teach that this is the voice of somebody, when I recognize it myself; or should inform me that my friend speaks, when I myself hear and understand him speaking?3
So the identification of Scripture for Whitaker is much like being able to discern between external stimuli using the relevant sense. If presented with a variety of sounds, people with proper hearing will be able to distinguish between the various noises and identify which is someone speaking and which is, say, merely the sound of the wind blowing through trees.
The Internal Testimony of the Holy Spirit
Now, it seems Stapleton and other Catholics objected to this position because Scripture is not like hearing someone else speak. Yet Whitaker here says that the Holy Spirit gives an internal witness to the believer so that he may understand that God is speaking through Scripture (emphasis in original):
But they object that we cannot recognize the voice of God, because we do not hear God speaking. This I deny. For those who have the Holy Spirit, are taught of God: these can recognise the voice of God as much as any one can recognize a friend, with whom he hath long and familiarly lived, by his voice. Nay, they can even hear God. For so Augustine (Ep. III.), "God addresses us every day. He speaks to the heart of every one of us."4 If we do not understand, the reason is because we have not the Spirit, by which our hearts should be enlightened. With respect to us, therefore, the authority of scripture depends upon, and is made clear by, the internal witness of the Holy Spirit; without which, though you were to hear a thousand times that this is the word of God, yet you could never believe in such a manner as to acquiesce with an entire assent.5
This seems reasonable enough. If, indeed, the Holy Spirit is real, then its internal testimony is valid enough for individual Christians to know that Scripture is true.
And if the Holy Spirit testifies to the truthfulness of Scripture, the role Stapleton wishes for the Magisterium to play is no longer appropriate or even possible.
Now, the testimony of the Holy Spirit might very well be sufficient for the individual Christian, but how would an external case be made for the truthfulness of Scripture? Whitaker's reasons can be summarized as follows6:
1. The majestic and unique nature of the doctrines of Scripture as compared with the writings of the greatest of pagan philosophers or Christian theologians. This is true even for those works that were doubted by some early Christians, such as Jude, 2 Peter, 2 John and 3 John.
2. The "simplicity, purity, and divinity of the style" in which Scripture is written as compared with the philosophers Plato, Aristotle, Cicero, etc.
3. The fact that the books of Moses are older than any other work, containing the oldest and purest of all historical knowledge, giving it more authority than any other work.
4. The fulfillment of prophecies such as 1 Kings 13:2, Isaiah 44:28, etc.
5. The prodigious miraculous accounts contained in Scripture.
6. The repeated and failed attempts of God's enemies to destroy the documents (perhaps copies) of Scripture. These enemies sometimes came to see that God wrote Scripture after suffering punishments for attempting to destroy them.
7. The blood and confessions of martyrs to its truthfulness.
8. The changed or unexpected character of many of the authors of Scripture:
Who was Moses, before he was called by God? First, a courtier in Egypt, then a shepherd, finally, endued with the richest outpouring of the Spirit, he became a prophet, and the leader of the people of Israel. Who was Jeremiah? A man, incapable, as himself testifies, of any eloquence. Who was David? A youth and a shepherd. Who Peter? A fisherman, an ignorant and illiterate person. Who John? A man of the same low rank. Who was Matthew? A publican, altogether a stranger to holy things. Who was Paul? An enemy and persecutor of that doctrine which he afterwards professed. Who was Luke? A physician. How could such men have written so divinely without the divine inspiration of the Holy Ghost? They were, almost all, illiterate men, learned in no accomplishments, taught in no schools, imbued with no instruction; but afterwards summoned by a divine call, marked out for this office, admitted to the counsels of God: and so they committed all to writing with the exactest fidelity; which writings are now in our hands.7
While the list contains some rather valid reasons, not all of these will be acceptable to all persons (for example, the third is, perhaps, a fallacious appeal to antiquity), and we might very well employ refined versions of these arguments (or different ones altogether) should we be pressed to make our own attempt at the question of external verification.
However, if any readers wish to object to this list, it would be best to recognize that Whitaker seems to be making a cumulative case. All the various reasons must be considered together and in relation to one another. We cannot, as some skeptics do with respect to the Resurrection, object to, for example, the seventh reason by noting that many people have died for beliefs we know to be false, therefore, the seventh reason is completely worthless and may be discarded as such. No, the purpose of the seventh reason does not seem to be merely to say that martyrdom proves that a position is true. Rather, it seems to suggest that martyrdom demonstrates the sincerity of those who die for their cause, making it more likely that the position to which they attest and willingly die is true.
All this to say that this is an effective list, but we are cautioned still:
These topics may prove that these books are divine, yet will never be sufficient to bring conviction to our souls so as to make us assent, unless the testimony of the Holy Spirit be added. When this is added, it fills our minds with a wonderful plenitude of assurance, confirms them, and causes us most gladly to embrace the scriptures, giving force to the preceding arguments. Those previous arguments may indeed urge and constrain us; but this (I mean the internal testimony of the Holy Spirit) is the only argument which can persuade us.8
A useful reminder for those of us involved in apologetics.
1. Whitaker, Disputations, 288-289.
2. 2 Timothy 3:16; 2 Peter 1:12, 19; Psalm 119:105-112.
3. Whitaker, Disputations, 289-290.
4. The citation for this quote is "Ep. 137. Opp. T. II. 528. Bassan. 1797." If anyone knows where to find this in a modern work, I would be grateful to read it in its fuller context.
5. Whitaker, Disputations, 290.
6. Ibid. 293-294.
7. Ibid., 294.
8. Ibid., 294-295.