Martin Luther stated the classic Protestant understanding of the perspicuity of Scripture in his own favorite (and arguably most important) writing, The Bondage of the Will (from translation by Henry Cole, Grand Rapids, MI: Baker Book House, 1976, 25-27,29; emphasis in original):
But, that there are in the Scriptures some things abstruse, and that all things are not quite plain, is a report spread abroad by the impious Sophists; by whose mouth you speak here, Erasmus . . .
This indeed I confess, that there are many places in the Scriptures obscure and abstruse; not from the majesty of the things, but from our ignorance of certain terms and grammatical particulars; but which do not prevent a knowledge of all the things in the Scriptures . . .
All the things, therefore, contained in the Scriptures, are made manifest, although some places, from the words not being understood, are yet obscure . . .And, if the words are obscure in one place, yet they are clear in another . . . For Christ has opened our understanding to understand the Scriptures . . .
Therefore come forward, you and all the Sophists together, and produce any one mystery which is still abstruse in the Scriptures. But, if many things still remain abstruse to many, this does not arise from obscurity in the Scriptures, but from their own blindness or want of understanding, who do not go the way to see the all-perfect clearness of the truth . . . Let, therefore, wretched men cease to impute, with blasphemous perverseness, the darkness and obscurity of their own heart to the all-clear scriptures of God . . .
If you speak of the internal clearness, no man sees one iota in the Scriptures, but he that hath the Spirit of God . . . If you speak of the external clearness, nothing whatever is left obscure or ambiguous; but all things that are in the Scriptures, are by the Word brought forth into the clearest light, and proclaimed to the whole world.
This is what I call the "sin" explanation, which is often brought forth to account for the obvious fact that agreement on Scriptural content and meaning on many, many doctrines has never been achieved by Protestantism, to put it very mildly. It is woefully inadequate, and I assert that Luther's principle crumbles in light of the factual considerations below. One cannot invoke "sin" as the all-encompassing reason for Christian disagreement (as Luther - typically - does). That is absurdly simplistic as well as clearly uncharitable and judgmental.
Most conservative, classical, evangelical, "Reformation" Protestants agree with Luther's sentiments above totally or largely and hold to the view that - when all is said and done - the Bible is basically perspicuous (able to be clearly understood) in and of itself, without the absolute necessity for theological teaching, scholarly interpretation, and the authority of the Church (however defined).
This is not to say that Protestants are consciously taught to ignore Christian historical precedent altogether and shun theological instruction (although, sadly, the tendency of a-historicism and anti-intellectualism is strong in many circles). Rather, perspicuity is usually said to apply to doctrines "essential" for salvation.
Accordingly, it follows that whatever is necessary for salvation can be found in the Bible by any literate individual without the requisite assistance of an ecclesiastical body. This is presupposed in, for example, the widespread practice of passing out Bibles to the newly-evangelized, oftentimes with no provision made for further guidance and supervision.
But what could possibly be imagined as more fatal to this abstract view than the multiplicity of denominations in Protestantism? The Bible is indeed more often than not quite clear when approached open-mindedly and with a moral willingness to accept its teachings. I assume this myself, even as a Catholic. But in actual fact many Christians (and also heretics or "cultists") distort and misunderstand the Bible, or at the very least, arrive at contradictory, sincerely-held convictions.
This is the whole point from the Catholic perspective. Error is necessarily present wherever disagreements exist - clearly not a desirable situation, as all falsehood is harmful (for example, John 8:44, 16:13, 2 Thessalonians 2:10-12, 1 John 4:6). Perspicuity (much like Protestantism as a whole) might theoretically be a good thing in principle, and on paper, but in practice it is unworkable and untenable.
Yet Protestant freedom of conscience is valued more than unity and the certainty of doctrinal truth in all matters (not just the core issues alone). The inquirer with newfound zeal for Christ is in trouble if he expects to easily attain any comprehensive certainty within Protestantism. All he can do is take a "head count" of scholars and pastors and evangelists and Bible Dictionaries and see who lines up where on the various sides of the numerous disagreements.
Or else he can just uncritically accept the word of whatever denomination he is associated with. In effect, then, he is no better off than a beginning philosophy student who prefers Kierkegaard to Kant - the whole procedure (however well-intentioned) is arbitrary and destined to produce further confusion.
The usual Protestant reply to this critique is that denominations differ mostly over secondary issues, not fundamental or central doctrines. This is often and casually stated, but when scrutinized, it collapses under its own weight. Right from the beginning, the fault lines of Protestantism appeared when Zwingli and Oecolampadius (two lesser Reformers) differed with Luther on the Real Presence, and the Anabaptists dissented on the Eucharist, infant baptism, ordination, and the function of civil authority.
Luther regarded these fellow Protestants as "damned" and "out of the Church" for these reasons. Reformers John Calvin and Martin Bucer held to a third position on the Eucharist (broadly speaking), intermediate between Luther's Real Presence (consubstantiation) and Zwingli's purely symbolic belief. By 1577, the book 200 Interpretations of the Words, "This is My Body" was published at Ingolstadt, Germany. This is the fruit of perspicuity, and it was quick to appear.
Protestants will often maintain that the Eucharist and baptism, for instance, are neither primary nor essential doctrines. This is curious, since these are the two sacraments that the majority of Protestants accept. Jesus said (John 6:53): Unless you eat the flesh of the Son of man and drink his blood, you have no life in you. This certainly sounds essential, even to the extent that a man's salvation might be in jeopardy.
St. Paul, too, regards communion with equally great seriousness and of the utmost importance to one's spiritual well-being and relationship with Jesus Christ (1 Corinthians 10:14-22, 11:23-30). Thus we are already in the realm of salvation - a primary doctrine. Lutherans and many Anglicans (for example, the Oxford Tractarians and C.S. Lewis), believe in the Real Presence, whereas most evangelicals do not, yet this is not considered cause for alarm or even discomfort.
Protestants also differ on other soteriological issues: most Methodists, Anglicans, Lutherans, pentecostals, some Baptists, and many non-denominationalists and other groups are Arminian and accept free will and the possibility of falling away from salvation (apostasy), while Presbyterians, Reformed and a few Baptist denominations and other groups are Calvinist and deny free will and the possibility of apostasy for the elect. In contrast to the former denominations, the latter groups have a stronger view of the nature of original sin, and deny that the Atonement is universal.
Traditional, orthodox Methodism (following founder John Wesley) and many "high church" Anglicans have had views of sanctification (that is, the relationship of faith and works, and of God's enabling and preceding grace and man's cooperation) akin to that of Catholicism. These are questions of how one repents and is saved (justification) and of what is required afterwards to either manifest or maintain this salvation (sanctification and perseverance). Thus, they are primary doctrines, even by Protestant criteria.
The same state of affairs is true concerning baptism, where Protestants are split into infant and adult camps. Furthermore, the infant camp contains those who accept baptismal regeneration (Lutherans, Anglicans, and to some extent, Methodists), as does the adult camp (Churches of Christ and Disciples of Christ). Regeneration absolutely has a bearing on salvation, and therefore is a primary doctrine. The Salvation Army and the Quakers don't baptize at all (the latter doesn't even celebrate the Eucharist). Thus, there are five distinct competing belief-systems among Protestants with regard to baptism.
Scripture seems to clearly refer to baptismal regeneration in Acts 2:38 (forgiveness of sins), 22:16 (wash away your sins), Romans 6:3-4, 1 Corinthians 6:11, Titus 3:5 (he saved us, . . . by the washing of regeneration), and other passages.
For this reason, many prominent Protestant individuals and denominations have held to the position of baptismal regeneration, which is anathema to the Baptist / Presbyterian / Reformed branch of Protestantism - the predominant evangelical outlook at present. We need look no further than Martin Luther himself, from whom all Protestants inherit their understanding of both sola Scriptura and faith alone (sola fide) as the prerequisites for salvation and justification. Luther largely agrees with the Catholic position on sacramental and regenerative infant baptism:
Little children . . . are free in every way, secure and saved solely through the glory of their baptism . . . Through the prayer of the believing church which presents it, . . . the infant is changed, cleansed, and renewed by inpoured faith. Nor should I doubt that even a godless adult could be changed, in any of the sacraments, if the same church prayed for and presented him, as we read of the paralytic in the Gospel, who was healed through the faith of others (Mark 2:3-12). I should be ready to admit that in this sense the sacraments of the New Law are efficacious in conferring grace, not only to those who do not, but even to those who do most obstinately present an obstacle.Likewise, in his Large Catechism (1529), Luther writes:
(The Babylonian Captivity of the Church, 1520, from the translation of A.T.W. Steinhauser, Philadelphia: Fortress Press, rev. ed., 1970, 197)
Expressed in the simplest form, the power, the effect, the benefit, the fruit and the purpose of baptism is to save. No one is baptized that he may become a prince, but, as the words declare [of Mark 16:16], that he may be saved. But to be saved, we know very well, is to be delivered from sin, death, and Satan, and to enter Christ's kingdom and live forever with him . . . Through the Word, baptism receives the power to become the washing of regeneration, as St. Paul calls it in Titus 3:5 . . . Faith clings to the water and believes it to be baptism which effects pure salvation and life . . .Anglicanism concurs with Luther on this matter. In its authoritative Thirty-Nine Articles (1563, language revised 1801), Article 27, Of Baptism, reads as follows:
When sin and conscience oppress us . . . you may say: It is a fact that I am baptized, but, being baptized, I have the promise that I shall be saved and obtain eternal life
for both soul and body . . . Hence, no greater jewel can adorn our body or soul than baptism; for through it perfect holiness and salvation become accessible to us . . .
(From edition by Augsburg Publishing House (Minneapolis), 1935, sections 223-224, 230, 162, 165)
Baptism is not only a sign of profession, and mark of difference, whereby Christian men are discerned from others that be not christened, but it is also a sign of Regeneration or New-Birth, whereby, as by an instrument, they that receive Baptism rightly are grafted into the Church; the promises of the forgiveness of sin, and of our adoption to be the sons of God by the Holy Ghost, are visibly signed and sealed; Faith is confirmed, and Grace increased by virtue of prayer unto God.
The Baptism of young Children is in any wise to be retained in the Church, as most agreeable with the institution of Christ.
(From The Book of Common Prayer, New York: The Seabury Press, 1979, 873)
The venerable John Wesley, founder of Methodism, who is widely admired by Protestants and Catholics alike, agreed, too, that children are regenerated (and justified initially) by means of infant baptism. From this position he never wavered. In his Articles of Religion (1784), which is a revised version of the Anglican Articles, he retains an abridged form of the clause on baptism (No. 17) , stating that it is "a sign of regeneration, or the new birth."
The doctrine of baptism in particular, as well as other doctrinal disputes mentioned above, illustrate the irresolvable Protestant dilemma with regard to its fallacious notion of perspicuity. Again, the Bible is obviously not perspicuous enough to efficiently eliminate these differences, unless one arrogantly maintains that sin always blinds those in opposing camps from seeing obvious truths, which even a "plowboy" (Luther's famous phrase) ought to be able to grasp. Obviously, an authoritative (and even infallible) interpreter is needed whether or not the Bible is perspicuous enough to be theoretically understood without help. Nothing could be clearer than that. Paper infallibility is no substitute for conciliar and/or papal infallibility, or at least an authoritative denominational (Creedal / Confessional) authority, if nothing else.
The conclusion is inescapable: either biblical perspicuity is a falsehood or one or more of the doctrines of regeneration, justification, sanctification, salvation, election, free will, predestination, perseverance, eternal security, the Atonement, original sin, the Eucharist, and baptism, all "five points" of Calvinism (TULIP) and issues affecting the very gospel itself - are not central. Protestants can't have it both ways.
Or, of course, people like Martin Luther (due to his beliefs in the Real Presence and baptismal regeneration), John Wesley, C.S. Lewis, and entire denominations such as Methodists, Anglicans, Lutherans, Churches of Christ, various Pentecostal groups, and the Salvation Army can be read out of the Christian faith due to their "unorthodoxy," as defined by the self-proclaimed "mainstream" evangelicals such as Baptists, Presbyterians and Reformed (even so the last two groups baptize infants, although they vehemently deny that this causes regeneration, whereas Baptists don't). Since most Protestants are unwilling to anathematize other Protestants, perspicuity dissolves into a boiling cauldron of incomprehensible contradictions, and as such, must be discarded or at the very least seriously reformulated in order to harmonize with the Bible and logic.
Whether one accepts the Tradition and teachings of the Catholic Church or not, at least it courageously takes a stand on any given doctrine and refuses to leave whole areas of theology and practice perpetually up for grabs and at the mercy of the "priesthood of scholars" and the individual's private judgment, which in turn often reduces to mere whim, fancy, or subjective preference, usually divorced from considerations of Christian history and consensus. For this so-called "dogmatism" and lack of "flexibility," the Catholic Church is often reviled and despised. But for those of us who are seeking to be faithful to Christ within its fold, this is regarded, to the contrary, as its unique glory and majesty, much preferable to the morass of competing truth-claims (i.e., relativism) which prevail within Protestantism (even among the subgroup of evangelicals).
Orthodox Catholics believe that Christians can place full confidence in the firmly-established Tradition which is found not only in Holy Scripture, but in the received doctrines of the Catholic Church, appointed by our Lord Jesus Christ as the Guardian and Custodian of the faith which was once for all delivered to the saints (Jude 3).