You better be grateful

I'm reading Gulliver's Travels to Lucas.  I stumbled across this quote, which I thought was an appropriate meditation with Thanksgiving just around the corner:

"Ingratitude is among them a capital crime, as we read it to have been in some other countries; for they reason thus, that whoever makes ill returns to his benefactor, must needs be a common enemy to the rest of mankind, from whom he hath received no obligation, and therefore such a man is not fit to live."  --Gulliver's Travels