New opinions often appear first as jokes and fancies, then as blasphemies and treason, then as questions open to discussion, and finally as established truths.
We should not be so taken up in the search for truth, as to neglect the needful duties of active life; for it is only action that gives a true value and commendation to virtue.
So with truth - there is a certain moment when one can say, this is the truth and here I put a dot, a stop, and I go to another thing. A judge has to put an end to a deliberation. But for a historian, theres never an end to the past. It can go on and on and on.
To all new truths, or renovation of old truths, it must be as in the ark between the destroyed and the about-to-be renovated world. The raven must be sent out before the dove, and ominous controversy must precede peace and the olive wreath.