More poetry from ancient greece

This is some poetry I found while examining what I first thought to be graffiti on the node of a Grecian urn:

The crowds are dark and silent, like the storm that brews above;
There is no call for brotherhood, no laugh or word of love.
They wait in dreadful silence still, they know they are not wise or brave;
in fear we stand in huddled mass,
each small as a single blade of grass;
but one great wave.

This wave is dark and fearful now, the tide has turned against its strand,
each single drop of water flees,  it does not try to make a stand.
The crowd knows an execution waits, they know that there is death for some;
But we are an obstinate wave indeed; and we won't run.

What plotters scheme in secret talks, what mobsters yell to angered crowds;
What tyrants at frail freedom scoff, when fists are shaken at the clouds,
What rings soundless on our stubborn ears, toiling heat from the burning sun;
Oh we have seen these signs before, but we won't run.

The tide has turned a thousand times, countless grains have been ground to dust,
the heavy sand beneath us heaves, it hears the call and seaward leaves,
But to stand firmly in the draining sand,
to raise our stained and grimy hands, for we must stay and we must stand,
Because we won't run.

Let tyrant trumpets about us blare, let new orders brandish spangled flags,
Let the seamless empty oceans stare, let them call our banner rags;
Let their leaders pose and call themselves The One;
What motley fools we are indeed, for we won't run.