and extent of the surrounding universe, of which he
occupies but a small portion. The diurnal swiftness of the orbs that
move round the Earth he attributes to God's omnipotence, that to
material bodies 'could add speed almost spiritual.'

The Angel, after alluding to his rapid flight through space, suggests
that God placed heaven so far from Earth that man might not presume to
inquire into things which it would be of no advantage for him to know.
He then suddenly changes to the Copernican system, which he lucidly
describes in the following lines:--

What if the Sun
Be centre to the World, and other stars
By his attractive virtue and their own
Incited, dance about him various rounds?
Their wandering course, now high, now low, then hid,
Progressive, retrograde, or standing still,
In six thou seest; and what if, seventh to these
The planet Earth, so steadfast though she seem,
Insensibly three different motions move?
Which else to several spheres thou must ascribe,
Moved contrary with thwart obliquities,
Or save the Sun his labour, and that swift
Nocturnal and diurnal rhomb supposed
Invisible else above all stars, the wheel
Of day and night; which needs not thy belief,
If Earth, industrious of herself, fetch day
Travelling east, and with her part averse
From the Sun's beam meet night, her other part
Still luminous by his ray. What if that light,
Sent from her through the wide transpicuous air,
To the terrestrial Moon be as a star,
Enlightening her by day, as she by night
This Earth--reciprocal, if land be there,
Fields and inhabitants? Her spots thou seest
As clouds, and clouds may rain, and rain produce
Fruits in her softened soil, for some to eat
Allotted there; and other Suns, perhaps,
With their attendant Moons, thou wilt descry,
Communicating male and female light--
Which two great sexes animate the World,
Stored in each orb perhaps with some that live.
For such vast room in Nature unpossessed
By living soul, desert and desolate,
Only to shine, yet scarce to contribute
Each orb a glimpse of light, conveyed so far
Down to this habitable, which returns
Light back to them, is obvious to dispute.--viii. 122-58.

The Copernican theory, which is less complicated and more easily
understood than the Ptolemaic, is described by Milton with accu