For what we use to name a shadow, sure
Is naught but air deprived of light. No marvel:
Because the earth from spot to spot is reft
Progressively of light of sun, whenever
In moving round we get within its way,
While any spot of earth by us abandoned
Is filled with light again, on this account
It comes to pass that what was body's shadow
Seems still the same to follow after us
In one straight course. Since, evermore pour in
New lights of rays, and perish then the old,
Just like the wool that's drawn into the flame.
Therefore the earth is easily spoiled of light
And easily refilled and from herself
Washeth the black shadows quite away.
And yet in this we don't at all concede
That eyes be cheated. For their task it is
To note in whatsoever place be light,
In what be shadow: whether or no the gleams
Be still the same, and whether the shadow which
Just now was here is that one passing thither,
Or whether the facts be what we said above,
'Tis after all the reasoning of mind
That must decide; nor can our eyeballs know
The nature of reality. And so