However positive any one's persuasion may be, not only of the falsity, but of the pernicious consequences—not only of the pernicious consequences, but (to adopt expressions which I altogether condemn) the immorality and impiety of an opinion; yet if, in pursuance of that private judgment, though backed by the public judgment of his country or his contemporaries, he prevents the opinion from being heard in its defence, he assumes infallibility.