It is the task of all education to change certain conscious actions and habits into more or less unconscious ones; and the history of mankind is in this sense its education. The philologist now practises unconsciously a number of such occupations and habits. It is my object to ascertain how his power, that is, his instinctive methods of work, is the result of activities which were formerly conscious, but which he has gradually come to feel as such no longer: but that consciousness consisted of prejudices. The present power of philologists is based upon these prejudices, for example the value attached to the ratio as in the cases of Bentley and Hermann. Prejudices are, as Lichtenberg says, the art impulses of men.