Go, Soul, the body's guest,

Upon a thankless arrant:

Fear not to touch the best,

The truth shall be thy warrant:

Go, since I needs must die,

And give the world the lie.

Sir Walter Raleigh (1552-1618): The Lie.

How sharper than a serpent's tooth it is

To have a thankless child!

William Shakespeare (1564-1616): King Lear. Act i. Sc. 4.

Ah, how unjust to Nature and himself

Is thoughtless, thankless, inconsistent man!

Edward Young (1684-1765): Night thoughts. Night ii. Line 112.

And strictly meditate the thankless Muse.

John Milton (1608-1674): Lycidas. Line 66.