In short, all observers of Venus agree in thinking that her atmosphere,
to a greater or less extent, serves as a mask to conceal her real
features, and the possibilities of so extensive an atmosphere with
reference to an adjustment of the peculiar conditions of the planet to
the requirements of life upon it, are almost unlimited. If we could
accurately analyze that atmosphere we would have a basis for more exact
conclusions concerning Venus's habitability.

But the mere existence of the atmosphere is, in itself, a strong
argument for the habitability of the planet, and as to the temperature,
we are really not compelled to imagine special adaptations by means of
which it may be brought into accord with that prevailing upon the earth.
As long as the temperature does not rise to the _destructive_ point,
beyond which our experience teaches that no organic life can exist, it
may very well attain an elevation that would mean extreme discomfort
from our point of view, without precluding the existence of life even in
its terrestrial sense.

And would it not be unreasonable to assume that vital phenomena on other
planets must be subject to exactly the same limitations that we find
circumscribing them in our world? That kind of assumption has more than
once led us far astray even in dealing with terrestrial conditions.

It is not so long ago, for instance, since life in the depths of the sea
was deemed to be demonstrably impossible. The bottom of the ocean, we
were assured, was a region of eternal darkness and of frightful
pressure, wherein no living creatures could exist. Yet the first dip of
the deep-sea trawl brought up animals of marvelous delicacy of
organization, which, although curiously and wonderfully adapted to live