John Stuart Mill in his classic book On Liberty takes pains to point out that he is not saying that there must always be dissenting opinions. He does not say that a truth unanimously adopted does not at that moment stop to be a truth. Mill admits that when a doctrine does achieve near universal acceptance, that makes it more difficult. That is a serious drawback, because the necessity of explaining it to opponents or defending it against their attacks is most beneficial. But the absence of that does not end the matter. He says then teachers or others who are trying to persuade must find a substitute. They must find “some contrivance for making the difficulties of the question present to the learner’s consciousness, as if they were pressed upon him by a dissentient champion, eager for conversion.”
This is precisely the method adopted by the legal system. We call it the adversarial system. Both sides of a dispute are represented by competent advocates who make sure that the judge or trier of fact or law is fully apprised of all arguments in favor of a proposition or against it. That is why judges never want to proceed unless both parties to a dispute are represented by capable advocates. If they do not ensure this, the judge might make a mistake. Of course, even under the adversarial system, judges can make mistakes, but the chances are much less when that system is respected. It is a system that has stood the test of time.
Mill uses another example of a contrivance to substitute for full argument by both parties. This is the use of the Socratic method so loved by my insurance law professor. The system was based on a proper understanding of the classics of Greek philosophy brought forth by Plato. I remember reading some of those dialogues in my first year of university. Plato had Socrates often start a discussion by considering a commonly held opinion and then chipping away at it. Socrates referred to himself as an annoying “gadfly.” Annoying yes; but essential to the task of seeking the truth. Mill put it this way,
“The Socratic dialectics, so magnificently exemplified in the dialogues of Plato, were a contrivance of this description. They were essentially a negative discussion of the great questions of philosophy and life, directed with consummate skill to the purpose of convincing any one who had merely adopted the commonplace of received opinion that he did not understand the subject—that he as yet attached no definite meaning to the doctrines he professed; in order that, becoming aware of his ignorance, he might be put in the way to obtain a stable belief, resting on a clear apprehension both of the meaning of doctrines and of their evidence.”
Mill also mentioned how a similar approach was used by the famous “school disputations of the Middle Ages.” This technique was designed to make sure that a young student of theology understood fully his own position and in consequence the position of his opponent so that he could successfully argue for one and confute the other. Of course, as Mill realised, the Schoolmen had one fatal flaw that Mill would never countenance by his methods, the Schoolmen accepted authority rather than reason. That made them infinitely inferior to the Socratic dialogues.
Law courts in the common law system suffer from the same defect. In matters of law Common Law courts accede to the authority of precedent that they are not free to challenge. At least theoretically that is the case. In practice sharp judges can often reach the conclusion they want to reach. While I love the adversarial system of Common law courts, I too am opposed to dogged obeisance to authority and think this is one of the reasons that courts make so many serious mistakes. If an aeronautical engineers used this method no one would want to fly.
For all of these reasons Mill emphasizes that it would be eminently foolish to disregard the opportunity to hear contrary opinions when they are offered. It is so difficult to create artificial contrivances to ensure that contrary views are heard, that decision makers should never forgo genuine contrary views. They should be embraced, never constrained. Mill concludes as follows, “If there are any persons who contest a received opinion, or who will do so if the law or opinion will let them, let us thank them for it, open our minds to listen to them, and rejoice that there is someone to do for us what we otherwise ought, if we have any regard for either the certainty or the vitality of our convictions to do with much greater labour ourselves.”
Free speech is always beneficial to the holder of opinions, whether true or false, provided the commentary is genuine and not frivolous or vexatious or totally absurd. As Mill said, such opinions should be “embraced, not constrained.’’ the contrary opinion and then deal with it.
That is why we need free speech.