A consensus toward error doesn’t make it a truth.
“It is naively assumed that the fact that the majority of people share certain ideas or feelings proves the validity of these ideas and feelings. Nothing is further from the truth. Consensual validation as such has no bearing on reason or mental health. Just as there is a folie à deux there is a folie à millions. The fact that millions of people share the same vices does not make these vices virtues, the fact that they share so many errors does not make the errors to be truths, and the fact that millions of people share the same mental pathology does not make these people sane.”

Erich Fromm (The Sane Society)