Much is said about the progress of science in these centuries. I should say that the useful results of science had accumulated, but that there had been no accumulation of knowledge, strictly speaking, for posteriry; for knowledge is to be aquired only by corresponding experience. How can be know what we are told merely? Each man can interpret another's experience only by his own.

A Week on the Concord and Merrimack Rivers. By Henry D. Thoreau (ed. 1862)