You fools! I and my fellows
Are ministers of Fate: the elements,
Of whom your swords are tempered, may as well
Wound the loud winds, or with bemocked-at stabs
Kill the still-closing waters, as diminish
One dowle that’s in my plume: my fellow-ministers
Are like invulnerable.

– William Shakespeare

The Tempest, Act 3, Scene 3. Ariel calls Alonso, Antonio and Sebastian fools because they think they can attack agents of Fate like him, having drawn their swords. Just as their swords cannot cut the winds or water, Ariel says that they cannot cut off even one of his feathers. He and his fellow spirits are invulnerable, he warns.