Cardinal Newman is often quoted as saying he would drink a toast to the Pope, but to conscience first.
Seeing the full quote, this is an unfortunate epitaph, as Newman wasn't about to drink to either:
"Certainly, if I am obliged to bring religion into after-dinner toasts, (which indeed does not seem quite the thing) I shall drink to the Pope, if you please, still, to Conscience first, and to the Pope afterwards"(A Letter Addressed to the Duke of Norfolk on Occasion of Mr. Gladstone's Recent Expostulation)
For Newman, ‘Conscience is not a longsighted selfishness, nor a desire to be consistent with oneself, but it is a messenger from Him who, in nature and in grace, speaks to us behind a veil and teaches and rules us by his representatives.Conscience is the aboriginal Vicar of Christ’
“Conscience has its rights because it has duties; but in this age, with a large portion of the public, it is the very right and freedom of conscience, to ignore a Lawgiver and Judge, to be independent of unseen obligations. It has become a license to take up any or no religion, to take up this or that and let it go again, to go to church, to go to chapel, to boast of being above all religions and to be an impartial critic of each of them.
Conscience is a stern monitor, but in this century it has been superseded by a counterfeit, which the eighteen centuries prior to it never heard of, and could not have mistaken for it, if they had. It is the right of self will”
Conscience is not: "is not the doctrine of private judgment as held by Protestants; for while with the latter private judgment is the arbiter of common events, with him it is decisive only ‘in very extraordinary and rare, nay, impossible cases’
Newman, A Letter Addressed to the Duke of Norfolk on Occasion of Mr. Gladstone's Recent Expostulation.
Pope John Paul II`s Letter to the Archbishop of Birmingham on the Centenary of Newman`s Death (18 June 1990)
The Theology of Cardinal Newman: One of the 'great teachers of the Church' by Cardinal Joseph Ratzinger (1990)
Auxiliary Bishop Anthony Fisher of Sydney, Australia, on Conscience and Authority delivered at the conference sponsored by the Pontifical Academy for Life and held in the Vatican March 2007 on "The Christian Conscience in Support of the Right to Life."