How does the Westminster Confession address the paradox of the Bible canon?

Chapter I, Article IV of the Westminster Confession (1647) reads: >The authority of the Holy Scripture, for which it ought to be believed, and obeyed, dependeth not upon the testimony of any man, or Church; but wholly upon God (who is truth itself) the author thereof: and therefore it is to be received, because it is the Word of God. This is very similar to Article I in the Chicago Statement on Biblical Inerrancy (1978): >WE AFFIRM that the Holy Scriptures are to be received as the authoritative Word of God. > >WE DENY that the Scriptures receive their authority from the Church, tradition, or any other human source. But nowhere does Scripture define its own composition. Would not some extra-Biblical source or sources have to be credited here as a relevant "testimony of man or Church" upon which the authority of Scripture itself must somehow depend? Such sources would include Church Fathers, Church councils, consensus within one's denomination or branch, trust in the Bible publisher(s), or, at the very least, personal belief or intuition. Is this a valid point? Has it ever been addressed by those who hold to the Westminster Confession? If so, how is it addressed?