In the Times article attacking the beatification of Newman, John Cornwell does not lose the opportunity to have a go at Pope Benedict whom he says is "clearly bent on sanitising Newman’s progressive Catholicism."
Cardinal Ratzinger's 1991 lecture on Conscience and Truth is well worth reading for an understanding of how he understands conscience and takes Newman's view that it is not merely something subjective but the voice of God within us. As he explains when discussing the Newman toast quote:
Modern man, who presupposes the opposition of authority to subjectivity, has difficulty understanding this. For him, conscience stands on the side of subjectivity and is the expression of the freedom of the subject. Authority, on the other hand, appears to him as the constraint on, threat to and even the negation of, freedom. So then we must go deeper to recover a vision in which this kind of opposition does not obtain.He goes on to show that the lifelong opposition to liberalism which Newman himself acknowledged when speaking on the occasion of his elevation to the cardinalate, led him to understand conscience as the perceptible and demanding voice of truth.
In this lecture, Ratzinger also made a point which is relevant to other attempts to smear him. He tells of a particular conversation with academic colleagues concerning the justifying power of the erroneous conscience. Someone countered that if this thesis were true, then the Nazi SS would be justified and we should seek them in heaven because "they carried out all their atrocities with fanatic conviction and complete certainty of conscience". Another colleague responded with assurance that this would be the case. Ratzinger comments:
Since that conversation, I knew with complete certainty that something was wrong with the theory of justifying power of the subjective conscience, that, in other words, a concept of conscience which leads to such conclusions must be false.