These, in the day when heaven was falling,
The hour when earth’s foundations fled,
Followed their mercenary calling,
And took their wages, and are dead.

Their shoulders held the sky suspended;
They stood, and earth’s foundations stay;
What God abandoned, these defended,
And saved the sum of things for pay.

The title of this poem is Epitaph on an Army of Mercenaries.

It’s one of my favorite poems of all time because it looks at things so
coldly and reminds us that sincerity is not the highest of
virtues.  Today we tend to think of virtue as a state of mind —
if you mean well, you’re a good person.  To Housman, as to the ancient Greeks, virtue was action, pure and simple.