"Earth produces nothing worse than an ungrateful man."
[Lat., Nil homine terra pejus ingrato creat.]
- Decimus Magnus Ausonius, Epigrams (CXL, 1)
. . . or . . .
"I hate ingratitude more in a man
Than lying, vainness, babbling, drunkenness,
Or any taint of vice whose strong corruption
Inhabits our frail blood."
- William Shakespeare, Twelfth Night (III, iv)