1) as Faith said, it is not technically correct to refer to the Church as ROMAN Catholic until the Bishop of ROME becomes dominant.
2) as I understand it, nearly all of our present canon was generally accepted by the early church. When some heretical canons were proposed (e.g. Marcion), church councils dealt with these heretical proposals and recognized the canon which had already been generally accepted.
In other words, the church councils did not determine the canon and force everyone to accept it. Rather, the canon had ALREADY been determined, and the church councils merely acknowledged and ratified what had already been generally accepted.
"Science without religion is lame, religion without science is blind." — Albert Einstein
I am very astonished that the scientific picture of the real world around me is very deficient. It gives us a lot of factual information, puts all of our experience in a magnificently consistent order, but it is ghastly silent about all and sundry that is really near to our heart, that really matters to us. It cannot tell us a word about red and blue, bitter and sweet, physical pain and physical delight; it knows nothing of beautiful and ugly, good or bad, God and eternity. Science sometimes pretends to answer questions in these domains, but the answers are very often so silly that we are not inclined to take them seriously. — Erwin Schroedinger