I'm no expert on this issue, but from what I know, the Catholic faith uses the "twin pillars" of Scripture and Tradition.
How can any one of them be "primary"?
Both of them are absolutely necessary to Catholicism. So much is not in scripture that Tradition isn't just "handy" -- it's downright necessary.
If you doubt it, just look at the mess the Protestants are in! How many protestant sects would even still qualify as religions? Any religion without dogmas, a claim of being true, or moral obligations is a joke, it seems to me.
Matthew