Well, consider racism, genocide, and oppression also have firm roots in consensus. We can all agree the moon is made of cheese or an innocent person is guilty. It does not make it right. It does not support good decisions or move us towards a better society. Manipulating people's beliefs to form a consensus of your liking is an art form, first used since the dawn of civilization to control people. There are countries in which the people are united in belief that their government rulers are gods, oppression is right, and one person should be the supreme ruler of everything. Consensus is a tool of ease and comfort. But a tool can be used for good or bad.
Copernicus did not care what the masses thought. He only pursued the Truth. The Wright Brothers didn't care that for centuries people believed human flight was impossible. They pursued the Truth that it was possible. Before our country was formed, the world held the consensus that Monarchy rule was just, right, and would forever be in place. The Truth was far from that.
The Truth, freedom of expression, and context of information is what breaks the bonds which turn people into cattle. I believe (just my personal belief, not trying to convince anyone) that Truth is far more important in decisions and change, than the consensus of the masses. Only with Truth, will the best decisions be determined. Consensus when Truth is realized becomes an operational triviality.
...the Truth will set you free (but first it will make you miserable) - Garfield
I agree that consensus is not the solution to everything. But what I think Dan's point is that if you don't know what to think, basing your actions on true consensus is better than basing them on perceived (fake) consensus.
Which is why 'mob mentality' is so dangerous. People doing what the crowd does can be extremely dangerous and situations escalate quickly with those ingredients. All I am saying is consensus is different than truth or critical thinking. The fact a group agrees on something is less important than the decision/position itself.
I absolutely agree with your point here @mrosenquist as I think a group consensus is definitely different than 1 person in that consensus doing all the research on a topic and finding more truth than another within that consensus.
This is an observation to your comment below which began, "You should know why you believe 2+2=4" and ended, " And rationality is about creating beliefs based on evidence."
So basically it would be really easy to gaslight you and the guy from the blog that you linked?!
His mind game was very interesting but I think it was somewhat flawed because when he said, "but memory would be absurd in the face of physical and mental confirmation that XXX - XX = XX." Surely memory and mental confirmation are the same thing? I see that he's trying to put them in separate compartments of his brain but that, I think, is his error: to do the sum and achieve mental confirmation he has to rely on his memory, surely? It just looks to me like he's changed the functionality of his brain to suit the outcome that he required for his mind game.
If I was in the situation that he described, my memory would continue to tell me that my eyes were seeing something odd and my mental arithmetic, based on my memory, would tell me the same. I would conclude that I was going mad or someone had found a way to gaslight me.
Having said that, I agree with what you said below, but I think that man made constructs as pure as maths are simply a bad example to illustrate what you were saying.
I am not sure I understand your issue with memory and mental confirmation. In the link I referenced earlier there is
I imagine the situation as follows: I remember that 3 - 2 = 1, but I keep seeing that XXX - XX = XX. My observation contradicts my memory, so I keep repeating the experiment, but only see XXX - XX = XX. So I go to my girlfriend and show her my experiment. If she is seeing what I am, I'll ask her what is 3 - 2. If she says 2, then I will start doubting my memory. If she is seeing something else than I am, I will start blaming my senses. If she is seeing and remembering the same as I, I will investigate further and try to find what is going on..
What you just described is fine but different to what the guy in the article described and his conclusion wasn't further investigation it was him having his mind changed. He had three things going on in order to prove why his mind would be changed: his memory of doing the sum previously, his observation and what he called mental confirmation, which was doing the sum in the present.
I believe that what he describes is impossible because he tried to separate two things that can't be separated.
It was a fun mental experiment but fundamentally flawed because his assumption of how memory works seems to be wrong.
There aren't many reliable things in the universe but pure maths is one of them-thank God!
That's exactly my point: consensus can be used to live a lie or to live the truth. But realizing the truth is a personal choice. It cannot be forced by consensus.