Reason and Ignorance, the opposites of each other, influence the great bulk of mankind. If either of these can be rendered sufficiently extensive in a country, the machinery of Government goes easily on. Reason obeys itself; and Ignorance submits to whatever is dictated to it.Reason and Ignorance are not opposites. Everybody is ignorant of far more than he or she knows. And as someone else said, the trouble isn't that people are ignorant, it's that they know so much that isn't so. Anyone who fancies him- or herself rational and free of ignorance will take a tumble in no time. As Jean-Paul Sartre wrote,
The rational man seeks the truth gropingly, he knows that his reasoning is only probable, that other considerations will arise to make it doubtful; he never knows too well where he's going, he is "open," he may even appear hesitant. But there are people who are attracted by the durability of stone. They want to be massive and impenetrable, they do not want to change: where would change lead them? This is an original fear of oneself and a fear of truth. And what frightens them is not the content of truth which they do not suspect but the very form of the true -- that hinge of indefinite approximation. It is as if their very existence were perpetually in suspension. They want to exist all at once and right away. They do not want acquired opinions, they want them to be innate; since they are afraid of reasoning, they want to adopt a mode of life in which reasoning and research play but a subordinate role, in which one never seeks but that which one has already found, in which one never becomes other than what one originally was ...The honest person knows that she's ignorant. That is the rationale for freedom of speech and debate: the fact that no one is free of ignorance, and so no one can decide infallibly in advance what opinion or belief should be suppressed.