C. S. Lewis in English Literature in the Sixteenth Century  
(p. 21) writes:

     It is largely to the humanists that we owe the curious 
     conception of the ‘classical’ period in a language, the 
     correct or normative period before which all was immature 
     or archaic and after which all was decadent. Thus Scaliger 
     tells us that Latin was ‘rude’ in Plautus, ‘ripe’ from 
     Terence to Virgil, decadent in Martial and Juvenal, senile in 
     Ausonius (Poetices  viii). Vives says much the same (De  
     tradendis disciplinis  iv). Vida, more wildly, makes all Greek 
     poetry after Homer a decline (Poeticorum  I, 139). When 
     once this superstition was established it led naturally to 
     the belief that good writing in the fifteenth or sixteenth 
     century meant writing which aped as closely as possible 
     that of the chosen period in the past. All real