Since thou readest in her what thou thyself hast there written,
And, to gladden the eye, placest her wonders in groups;--
Since o'er her boundless expanses thy cords to extend thou art able,
Thou dost think that thy mind wonderful Nature can grasp.
Thus the astronomer draws his figures over the heavens,
So that he may with more ease traverse the infinite space,
Knitting together e'en suns that by Sirius-distance are parted,
Making them join in the swan and in the horns of the bull.
But because the firmament shows him its glorious surface,
Can he the spheres' mystic dance therefore decipher aright?

Friedrich Schiller

http://www.poemhunter.com/poem/human-knowledge/