The notion of consensus has been appearing a fair bit recently in attempts to prove things or persuade people. As an example, global warming advocates like Al Gore have been claiming consensus among climate scientists that current Earth climate change is human-caused and destructive, hence requiring immediate action.
I've been quite familiar with that type of argument form for some time. Opponents of mine have frequently claimed "everyone believes X" when I'm saying something contrary to X. "Everyone" in that case, of course, refers to the small active population of web boards such as SDN.
It's a neat trick, really, since when stated to an uninformed audience such a thing can sound convincing.
It is obvious that the SDN treatment of dissent is no coincidence, when viewed in that light. Dissenting opinions are shuffled off into private forums, invisible to non-members. Dissenters themselves have been banned, spammed, harrassed, and even threatened. The very climate of well-poisoning vitriol and personal attacks also serves to keep potential dissenters away. And opposition elsewhere on the internet is sought out and attacked via board invasions, wiki-wars, 'sock puppets', and even occasional legal threats. Interested parties even moderate other boards on similar topics, with members of both holding the party line elsewhere. And let's not forget, of course, that even SW authors are attacked and maligned across the internet if they fail to subscribe to SDN views.
And this, so we're told, is consensus of opinion.
I think not. Even if one thinks consensus is important, one does not build it by such action. Ancient kings might've built a consensus that divine right existed, but they did so by slaughtering those who disagreed. That's not consensus at all, except in an ironic sense.
But even if we grant the claim of consensus, let's not kid ourselves that consensus is a determinant in matters of fact.
Truth is not determined by the number of adherents. That includes the collective opinion of a consensus. If everyone on Earth believed that 1+1=3, there would be consensus. However, the consensus opinion would be wrong.
Consensus is what is sought when there is ignorance. In jurisprudence, we could not know the facts with certainty, so consensus of peers was employed. Creating the appearance of consensus is also useful for swinging uninformed public opinion, which is why spin doctors try to claim that everyone believes such-and-such.
This, of course, is nothing new. Hence the fallacy of argumentum ad populam, or the appeal to the belief of the masses.
(Of course, one might argue that for this to be labelled a fallacy, it has been recognized as such by a group of logicians and thinkers through time, and as such could be wrong since that determination has been made by consensus. However, in doing so, one acknowledges that it's a fallacy anyway.)
Most of the above is not new to my readers, but the following is. A very nice and much more interesting take on the matter, the following link refers to a Parliament of Clocks. Much as a stopped clock is falsely said to be right twice a day when in reality it's just lucky, so too is a Parliament of Clocks misunderstood by laypeople:
(Incidentally, it's worth noting something tangentially relevant here. One SDN member quotes a statement of mine wherein I note that one does not determine fact by use of persuasive essays, but instead by reason. This quotation of me is apparently used to suggest that I'm a silly person, which is of course true. However, it's not true because I made that statement.
Persuasion occurs via many channels, and many forms of appeal. Appeals to authority, mass belief, emotion, and all manner of other things are valid when one seeks only to persuade. However, matters of fact are not determined with those. Reason is the only arbiter of fact. Write as many persuasive essays as you like, turn as many ears to your message as you can, but don't think for an instant that having people agree on that basis means that your position is factually accurate.)