My noble comrade JK cited this piece from Peter Leithart yesterday. Notably, I think this is the only time I have referenced Leithart on my blog, but I thought a quote from the cited piece was worth sharing:
If Jesus is Lord of His church; if the text of Scripture is uniquely from God, such that God speaks in human language; if Christ's Spirit can make His human words intelligible to human beings; if human beings can, under the guidance of the Spirit, speak God's words accurately and intelligibly to the church - then sola scriptura follows. Denying sola scriptura entails denial of one or more of those conditionals: God can't in fact speak without distortion in human language; or Scripture is not uniquely God's Word in human words; or Jesus is a titular but not a living Lord of His church.
This sums up well the Reformational sense of what sola scriptura meant. The force is not on throwing out all other sources of knowledge about God, but rather in recognizing the unique role of Scripture as the final authority that overrules all else. As the Westminster Confession says in 1.6, “The whole counsel of God concerning all things necessary for His own glory, man's salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture.”
One might ask if it is ironic that in discussing sola scriptura I turned to a tradition's confession (the Westminster Confession), but the very nature of the view of Scripture described above points to a clearly resounding “no.” The vows of the PCA make the distinction clear: the ordinand is to affirm believing that the Scriptures are “the only infallible rule of faith and practice,” but on the second count affirm only receiving and adopting the Confession “as containing the system of doctrine taught in the Holy Scriptures.” The Confession does not stand alone, but rather is entirely dependent for its authority on the Word of God.
That's sola scriptura.