Originalism and Experimentalism

Originalists believe that the intentions of the Founding Fathers should be the fundamental criterion of Judicial decision-making.  Now, the standard objection to Originalism is that intentions of the Founding Fathers reflect conditions that are obsolete.  However, a stronger counter-argument is on Epistemological grounds--that knowledge of the intentions of another, especially someone long deceased, is impossible, so what is being attributed to them is only the prejudices of the presumed knower, which are typically Conservative. Related to that objection is the charge that the source material for the alleged expression of intentions has been arbitrarily selected.  For example, on the basis of Washington's term "experiment", and of Jefferson's expression of admiration of Bacon, it could be asserted that the Constitution is an Experimentalist document, as its Amendments exemplify, so, likewise, an Originalist Judicial philosophy is Experimentalism.  At minimum, the range of counters to established Originalism only exposes the feebleness of the standard one.