our only field of direct observation. We must be
blind not to see this spectacle, deaf not to hear its reaching. On what
pretext could one suppose that our little globe which, as we have seen,
has received no privileges from Nature, is the exception; and that the
entire Universe, save for one insignificant isle, is devoted to vacancy,
solitude, and death?

We have a tendency to imagine that Life can not exist under conditions
other than terrestrial, and that the other worlds can only be inhabited
on the condition of being similar to our own. But terrestrial nature
itself demonstrates to us the error of this way of thinking. We die in
the water: fishes die out of the water. Again, short-sighted naturalists
affirm categorically that Life is impossible at the bottom of the sea:
1, because it is in complete darkness; 2, because the terrible pressure
would burst any organism; 3, because all motion would be impossible
there, and so on. Some inquisitive person sends down a dredge, and
brings up lovely creatures, so delicate in structure that the daintiest
touch must proceed with circumspection. There is no light in these
depths: they make it with their own phosphorescence. Other inquirers
visit subterranean caverns, and discover animals and plants whose organs
have been transformed by adaptation to their gloomy environment.

What right have we to say to the vital energy that radiates round every
Sun of the Universe: "Thus far shalt thou come, and no further"? In the
name of Science? An absolute mistake. The Known is an infinitesimal
island in the midst of the vast ocean of the Unknown. The deep seas
which seemed to be a barrier are, as we have seen, peopled with special
life. Some one objects: But after all, there is air there, there is
oxygen: oxygen is indispensable: a world without oxygen would be a
world of death, an eternally sterile desert. Why? Because we have not
yet come across beings that can breathe without air, and live without
oxygen? Another mistake. Even if we did not know of any, it would not
prove that they do not exist. But as it happens, we do know of such: the
_anaerobia_. These beings live without air, without oxygen. Better still:
oxygen kills them!

All the evidence goes to show that in interpreting as we ought the
spectacle of terrestrial life, and the positive facts acquired by
Science, we should enlarge the circle of our conceptions and our
judgments, and not limit extra-terrestrial existence to th