Many people seem to base their ideas about what is “true” and what is “false” upon some form of majority opinion. Sometimes this takes the form of a simple majority vote, sometimes of a statistical sampling, and other times the “general consensus” of all people around the world. Whatever the actual form, the basic premise here is that “truth” is best distinguished from “falsehood” by observing what most others believer to be the case.
This criterion of truth is closely related to the one which relies upon authority figures for distinguishing truth from error. Arguably, reliance upon majority opinion is actually another type of reliance upon authority, where the “authority figure” is the entire population rather than a single individual or a particular group.
Because of this, many of the critiques of relying upon authority as a criteria of truth apply here as well. There mere fact that a great many people believe a thing is a notoriously unreliable means for determining what is and is not true. After all, a person is quite capable of sincerely and firmly believing in the truth of something that is false; this does not change when we have large groups of people, so we must conclude that the majority of any group of people is capable of believing an error. History provides abundant evidence of this having happened.
The problem with criticizing majority opinion as a criterion of truth is that people typically hold democracy in high regard. In democracies, policies and laws are determined by majority opinion — so why not “truth” as well? What we must understand is that while the democratic process may be a just means for deciding what policy to follow, that doesn’t mean that this process always hits upon the best or most correct policy.
Democracy is a system of establishing political and social justice, not for establishing scientific, philosophical, or social truths. Physicists cannot determine the exact age of the universe by submitting the question to a vote. Philosophers cannot decide whether free will exists or not by meeting and casting ballots. Truth and justice are both important values, but that doesn’t mean that they can be arrived at via the same means.
By the same token, relying upon the “general consent” of the entire world doesn’t work as a valid means of separating truth from error. More commonly called “Consensus Gentium,” this method presumes that whenever some opinion is held by all, then of course we should accept it as true. This criterion is supposed to avoid one of the problems of majority opinion, namely the presence of those who disagree and who may, in theory, be right.
But just as the majority of a group is capable of sincerely believing an error, all of the members of a group are capable of sincerely believing the same error. The absence of any dissent, if that is even possible, is no guarantor of truth. If something is true, we must look beyond the mere fact that it is believed by most or all members of some population and discover if there are other, independent reasons for accepting their claims.
