Believing that if "everybody" or "many" believes it, it must be true. This is a fallacious argument that concludes that the proposition is true because many people believe it.
This fallacy is also known by other names: appeal to the masses, appeal to belief, appeal to the majority, appeal to democracy, appeal to popularity, argument by consensus, consensus fallacy, authority of the many, and bandwagon fallacy
Format of this fallacy
Most people believe that ''X' is true
So it must be true
But this kind of reasoning is not valid and it is a fallacy.
Lets say a large number of people are convinced to believe that 1+1=3 . But because a large number of people believe it this does not become true. 1+1=2 always - irrespective of how many people believe otherwise. Lets look at some examples from history
-At one point of time everybody believed that the Earth was flat. It didn't become true because many people believed in it
It was believed that the earth revolved around the sun. We now know the facts to be different, and that the earth revolves around the sun.
- Millions of people voted for this government. So this government can't be wrong
- Seven out of ten people in the Sales team believe this sales promotion won't work. Therefore it won't work
- So many people believe that X will make a great Prime Minister. So X will make a great Prime Minister
- Everybody believes X is guilty of the crime. He must be guilty
If Scientists were victims of this fallacy, we would truly have no progress in science at all.