The Seventh Ecumenical Council gave general approbation to all local councils (and the canons from these local councils) that were doctrinally orthodox. Some of these local councils included canons on the Canon of Scripture. The thing to note is that these canons on the Canon contained different lists of books (though there is a basic common set, and ALL the books that the Catholic Church now holds were held to be standard in ALL these local councils).
There is only one way to interpret this - namely, the Church has never depended on the written word ALONE for its Faith. The Faith is encompassed in ALL of Sacred Tradition which included (but not circumscribed by) the books of the Bible. Whatever books of Scripture were considered consonant with the orthodox Catholic Faith were accepted into the Canon. Different segments of the Church had different criteria. Some segments of the Church depended on the orthodoxy of the material, others depended on traditional use, others depended on apostolic authorship, and others yet a combination of these. This is why there are different Canons of Scripture in different parts of the Church. But the primordial rationale was always the same.
Blessings,
Marduk