Sola Scriptura 2
There were two causes for the Protestant Reformation: a material cause and a formal cause. The material cause was a dispute over the doctrine of justification by faith alone (Sola Fide). The formal cause was the disagreement over biblical authority (Sola Scriptura). The Reformers coined this phrase, Sola Scriptura, but certainly not this doctrine, when they rejected the two-source view of authority; meaning that the authority of church tradition is equal to the authority of the Scriptures.
Roman Catholics taught (and teach) that there are two sources of infallible special revelation, Scripture and tradition. Since they attributed this authority (Scripture) to the tradition of the church, they did not permit any person to interpret the Bible in a way that was contrary to this tradition. This is precisely what (Martin) Luther did, leading to his excommunication and the condemnation of this doctrine. The Reformers insisted there is only one written source of special revelation, the Bible. This is the sola of sola Scriptura. The chief reason for the word alone is the conviction that the Bible is inspired by God, while church creeds and pronouncements are the works of men. These lesser works may be accurate and brilliantly conceived, capturing the best insights of learned scholars; but they are not the inspired Word of God. (What is Reformed Theology 42)
God has established many institutions of authority. These include government (Romans 13), family (Ephesians 6:1-2), employers (Ephesians 6:5-9; Colossians 3:22-25; I Timothy 6:1-2), and the church (Matthew 18:15-20; I Timothy 3:1-7; Titus 1:5-9; Hebrews 13:7,17; I Peter 5:1-4). However, all of these authoritative structures are to be subordinate to the foundational authority of the Scriptures.
The two-source tradition of authority arose in the sixth century through the writings of Basil and Augustine. It further entrenched itself in the twelfth century, and later still in the fourteenth century with the writings of William of Ockham. “From the fourteenth century onward, then, we witness the parallel development of two opposing views: either Scripture alone is the preeminent authority which the church interprets or that the church is a second source of authority that supplements biblical revelation” (Modern Reformation 16:2). In the Protestant Reformation, we witness the Reformers embracing the former and the Catholic Church then, and later at the Council of Trent, committed to the latter.
John Calvin writes:
Nothing therefore can be more absurd than the fiction that the power of judging Scripture is in the Church and that on her nod its certainty depends. When the church receives it and gives it the stamp of her authority, she does not make that authentic which was otherwise doubtful or controverted but, acknowledging it as the truth of God, she, as in duty bounds shows her reverence by an unhesitating assent (Institutes 1:7:2).