There is some speech that the scholars say, and it's possible that we can name it a principle. It is:

The men are known by the truth and the truth is not known by the men.

The (statement): The men are known by the truth means: We do not say that they are upon truth except when we find the truth aiding them and the texts of the Quran and Sunnah aiding them. The (statement): And the truth is not known by the men means: You make that a man is your only passageway. You make him a scale and measuring tool for the truth. Whatever he says is the truth. Whatever he doesn't say is falsehood. Whatever he rejects is falsehood and it is possibly the truth. Whatever he accepts is the truth and it can possibly be in opposition to the command, falsehood (this is incorrect). Therefore (based upon this) we don't know the truth by way of the men. Indeed we only know the men by way of the truth.