“Over the Pope as expression of the binding claim of ecclesiastical authority, there stands one’s own conscience which must be obeyed before all else, even if necessary against the requirement of ecclesiastical authority [emphasis added]. This emphasis on the individual, whose conscience confronts him with a supreme and ultimate tribunal, and one which in the last resort is beyond the claim of external social groups, even the official Church, also establishes a principle in opposition to increasing totalitarianism.”
Joseph Ratzinger in: Commentary on the Documents of Vatican II ,Vol. V., pg. 134 (Ed) H. Vorgrimler, New York, Herder and Herder, 1967.
This is Cardinal Newman's position, isn't it? I also read cardinal Ratzinger on it, but Newman develops the principle over several pages. If you like I could probably find the text online for you.In "The Splendor of Truth" JPII also mentioned Newman in this context and spoke about conscience as man's "sanctuary".