Erasmus, letter 129, to James Batt (September 1500; tr. Francis Morgan Nichols):
I do wish, my dear Batt, that you knew Greek, both because I find Latin literature incomplete without it, and because it would make our intercourse more agreeable, if we took delight in the same studies.
The Latin, from Opus Epistolarum Des. Erasmi Roterodami
, ed. P.S. Allen, tom. I: 1484-1514
(Oxford: Clarendon Press, 1906; rpt. 1992), p. 301:
Verum Graece te scire, mi Batte, percupio, tum quod sine his literas Latinas mancas esse video, tum vt conuictus noster sit iucundior, si omnino iisdem studiis delectabimur.
On the first reason, cf. Eduard Fraenkel, review of E. K. Rand et al., edd., Servianorum in Vergilii Carmina Commentariorum Editionis Harvardianae Volumen II, quod in Aeneidos Libros I et II Explanationes Continet
(Lancaster: American Philological Society, 1946), in Journal of Roman Studies
38 (1948) 131-143 and 39 (1949) 145-154 (at 154):
It is a commonplace, and in theory everybody admits its truth, that almost everything in Latin literature can be properly understood only against a large Greek background.