References in classic literature ?
An impression due to this sort of intervening medium is called a perception, and is interesting to psychology on its own account, not merely as one of the set of correlated particulars which is the physical object of which (as we say) we are having a perception.
Such, then, are the differences of the arts with respect to the medium of imitation.
Only the rare and exceptional genius of Vergil and Milton could use the Homeric medium without loss of individuality: and this quality none of the later epic poets seem to have possessed.