Consider a couple of passages from All the King's Men:
We clocked off five miles more, and I said, "But suppose there isn't anything to find." And the Boss said, "There is always something." And I said, "Maybe not on the Judge." And he said, "Man is conceived in sin and born in corruption and he passeth from the stink of the didie to the stench of the shroud. There is always something."
For nothing is lost, nothing is ever lost. There is always the clue, the canceled check, the smeared lipstick, the footprint in the canna bed, the condom on the park path, the twitch in the old wound, the baby shoes dipped in bronze, the taint in the blood stream. And all times are one time, and those dead in the past never lived before our definition gives them life, and out of the shadow their eyes implore us.
That is what all of us historical researchers believe.
And we love truth.