Or else, as in a body is apportioned
  The fat and lean, so in like manner this
  Would in its volume interchange the leaves.

Were it the former, in the sun's eclipse
  It would be manifest by the shining through
  Of light, as through aught tenuous interfused.

This is not so; hence we must scan the other,
  And if it chance the other I demolish,
  Then falsified will thy opinion be.

But if this rarity go not through and through,
  There needs must be a limit, beyond which
  Its contrary prevents the further passing,

And thence the foreign radiance is reflected,
  Even as a colour cometh back from glass,
  The which behind itself concealeth lead.

Now thou wilt say the sunbeam shows itself
  More dimly there than in the other parts,
  By being there reflected farther back.

From this reply experiment will free thee
  If e'er thou try it, which is wont to be
  The fountain to the rivers of your arts.

Three mirrors shalt thou take, and two remove
  Alike from thee, the other more remote
  Between the former two shall meet thine eyes.

Turned towards these, cause that behind thy back
  Be placed a light, illuming the three mirrors
  And coming back to thee by all reflected.

Though in its quantity be not so ample
  The image most remote, there shalt thou see
  How it perforce is equally resplendent.

Now, as beneath the touches of warm rays
  Naked the subject of the snow remains
  Both of its former colour and its cold,

Thee thus remaining in thy intellect,
  Will I inform with such a living light,
  That it shall tremble in its aspect to thee.

Within the heaven of the divine repose
  Revolves a body, in whose virtue lies
  The being of whatever it contains.

The following heaven, that has so many eyes,
  Divides this being by essences diverse,
  Distinguished from it, and by it contained.

The other spheres, by various differences,
  All the distinctions which they have within them
  Dispose unto their ends and their effects.

Thus do these organs of the world proceed,
  As thou perceivest now, from grade to grade;
  Since from above they take, and act beneath.

Observe me well, how through this place I come
  Unto the truth thou wishest, that hereafter
  Thou mayst alone know how to keep the ford

The power and motion of the holy spheres,
  As from the artisan the hammer's craft,
  Forth from the blessed motors must proceed.

The heaven, which lights so manifold make fair,
  From the Intelligence profound, which turns it,
  The image takes, and makes of it a seal.

And even as the soul within your dust
  Through members different and accommodated
  To faculties diverse expands itself,

So likewise this Intelligence diffuses
  Its virtue multiplied among the stars.
  Itself revolving on its unity.

Virtue diverse doth a diverse alloyage
  Make with the precious body that it quickens,
  In which, as life in you, it is combined.

From the glad nature whence it is derived,
  The mingled virtue through the body shines,
  Even as gladness through the living pupil.

From this proceeds whate'er from light to light
  Appeareth different, not from dense and rare:
  This is the formal principle that produces,

According to its goodness, dark and bright."