able to learn, only a very small proportion of the visible worlds
scattered through space are fitted to be the abode of life does
not preclude the probability that among hundreds of millions of
such worlds a vast number are so fitted. Such being the case, all
the analogies of nature lead us to believe that, whatever the
process which led to life upon this earth--whether a special act
of creative power or a gradual course of development--through that
same process does life begin in every part of the universe fitted
to sustain it. The course of development involves a gradual
improvement in living forms, which by irregular steps rise higher
and higher in the scale of being. We have every reason to believe
that this is the case wherever life exists. It is, therefore,
perfectly reasonable to suppose that beings, not only animated,
but endowed with reason, inhabit countless worlds in space. It
would, indeed, be very inspiring could we learn by actual
observation what forms of society exist throughout space, and see
the members of such societies enjoying themselves by their warm
firesides. But this, so far as we can now see, is entirely beyond
the possible reach of our race, so long as it is confined to a
single world.





VIII

HOW THE PLANETS ARE WEIGHED