If the past is unknowable, so is the present and so must be the future — including our future.

Every present becomes the past — in an instant. William James talks about a specious present, an awareness which varies but is never very long. So the past can only be known as an edited version of the present. It cannot be complete. Our records of the past are either documented or preserved in personal memory. Neither can be complete.

Therefore any claim to know the past except as a reconstructed conjecture fails to meet our highest standards of accuracy and our most desired expectations. To be truthful about the past is, at best, a noble attempt to reconstruct the present from past clippings. At worst it is self-delusion which may also delude others unintentionally: it surely has such an effect.