Meteorology By Aristotle

Part 3

We must now explain why the sea is salt, and ask whether it eternally
exists as identically the same body, or whether it did not exist at
all once and some day will exist no longer, but will dry up as some
people think.

Every one admits this, that if the whole world originated the sea
did too; for they make them come into being at the same time. It follows
that if the universe is eternal the same must be true of the sea.
Any one who thinks like Democritus that the sea is diminishing and
will disappear in the end reminds us of Aesop's tales. His story was
that Charybdis had twice sucked in the sea: the first time she made
the mountains visible; the second time the islands; and when she sucks
it in for the last time she will dry it up entirely. Such a tale is
appropriate enough to Aesop in a rage with the ferryman, but not to
serious inquirers. Whatever made the sea remain at first, whether
it was its weight, as some even of those who hold these views say
(for it is easy to see the cause here), or some other reason-clearly
the same thing must make it persist for ever. They must either deny
that the water raised by the sun will return at all, or, if it does,
they must admit that the sea persists for ever or as long as this
process goes on, and again, that for the same period of time that
sweet water must have been carried up beforehand. So the sea will
never dry up: for before that can happen the water that has gone up
beforehand will return to it: for if you say that this happens once
you must admit its recurrence. If you stop the sun's course there
is no drying agency. If you let it go on it will draw up the sweet
water as we have said whenever it approaches, and let it descend again
when it recedes. This notion about the sea is derived from the fact
that many places are found to be drier now than they once were. Why
this is so we have explained. The phenomenon is due to temporary excess
of rain and not to any process of becoming in which the universe or
its parts are involved. Some day the opposite will take place and
after that the earth will grow dry once again. We must recognize that
this process always goes on thus in a cycle, for that is more satisfactory
than to suppose a change in the whole world in order to explain these
facts. But we have dwelt longer on this point than it deserves.