Erasmus, letter 31 (to an unnamed friend; tr. R.A.B. Mynors and D.F.S. Thomson):
I consider as lovers of books, not those who keep them hidden in their store-chests and never handle them, but those who, by nightly as well as daily use, thumb them, batter them, wear them out, who fill up the margins with annotations of many kinds, and who prefer the marks of a fault they have erased to a neat copy full of faults.
The Latin, from Opus Epistolarum Des. Erasmi Roterodami
, ed. P.S. Allen, tom. I: 1484-1514
(Oxford: Clarendon Press, 1906; rpt. 1992), p. 123:
Neque hi mihi libros amare videntur qui eos intactos ac scriniis abditos seruant, sed qui nocturna iuxta ac diurna contrectatione sordidant, corrugant, conterunt, qui margines passim notulis, hisque variis, oblinunt, qui mendi rasi vestigium quam mendosam compositionem malunt.