Institutio Oratoria

For even if a soldier cannot achieve the glory of Achilles in war, he will not despise fame such as fell to the lot of Ajax and Diomede, while those who cannot be Homers may be content to reach the level of Tyrtaeus. Nay, if men had been obsessed by the conviction that it was impossible to surpass the man who had so far shown himself best, those whom we now regard as best would never have reached such distinction, Lucretius

and Macer would never have been succeeded by Virgil, nor Crassus and Hortensius by Cicero, nor they in their turn by those who flourished after them.