[Mad Dawg]

I think as good a statement as any of what "Sola Scriptura" means is found in the Articles of Religion of the Church of England, to wit:

VI. Of the Sufficiency of the Holy Scriptures for Salvation.
Holy Scripture containeth all things necessary to salvation: so that whatsoever is not read therein, nor may be proved thereby, is not to be required of any man, that it should be believed as an article of the Faith, or be thought requisite or necessary to salvation. In the name of the Holy Scripture we do understand those canonical Books of the Old and New Testament, of whose authority was never any doubt in the Church.

I agree that Sola Scriptura, strictly interpreted, appears to be epistemologically impossible.

[TradicalRC]

Okay, except that this assertion about Scripture is ALSO extra-Scriptural, St. Paul says

And we charge you, brethren, in the name of our Lord Jesus Christ, that you withdraw yourselves from every brother walking disorderly and not according to the tradition which they have received of us.

Then of course the canon WAS decided by the Catholic Church under the guidance of the Holy Spirit, which Luther decided to edit. Makes me wonder why some Protestant sect hasn't decided that the Roman Church had no right or authority to decide canonicity and fashion something based on other early Christian writings and gnostic texts while we're at it.