sources mekorot - The truth does not depend on popular opinion?

I have heard multiple Rabbis say, mostly in the name of HaRaMBa"M, that the truth is not dependent on the number of adherents to a particular opinion. I apologize for lack of accuracy.

What is the source for such a statement?

Answer

Thanks to Google, YouTube (please see only the video description - I cannot vouch for the video's actual content) and finally Chabad.org, I found the original statement in Moreh Nevukhim 2:15¹:

כל דבר שהוכח, לא תוסיף אמתתו ולא יתחזק הנכון שבו בהסכמת כל העולם עליו, ולא תגרע אמתתו ולא יחלש הנכון שבו אם יחלקו כל אנשי הארץ עליו

Anything proven true does not become more true by virtue of the fact that the entire world agrees with it, nor less so even if the whole world disagrees with it.

---

^{1. Hebrew taken from R' Yosef Qafih's Moreh Nevukhim translation; English taken from Chabad.org article cited.}