Fr Joseph Ratzinger (1967):  Commentary on the Documents of Vatican II

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 requirements of ecclesiastical authority.
This emphasis on the individual, 
whose conscience confronts him with a supreme and ultimate tribunal, 
and one which is the last resort,
is beyond the claims of external social groups, 
even the official church, 
and also establishes a principle in opposition to totalitarianism.

Dr Brian  Lewis   Freedom of Conscience

Cardinal George Pell  True and False Conscience