rarefied condition, it becomes fire, and in its condensed
condition it progresses by stages from liquid to solid. And just
as the modern chemist is beginning to have good ground for
believing that all substances, or so-called elements, may be the
result of a series of differentiations and compositions of an
originally homogeneous substance, in spite of the fact that he is
not yet able to effect the transformations in his laboratory, so,
all those centuries ago, the Milesian sage seized on the same
root idea and made it the basis of a world philosophy. It is a
long cry from the old idea, familiar to Homer, that mist or
vapour is condensed air to the cosmology of a Herbert Spencer,
and yet nature is so rich in material for prompting intuitions of
her deepest truths that one ultimate cause of material evolution
was revealed in days when science was hardly brought to the
birth.

An examination, albeit cursory and partial, of this ancient
speculation, has thus revealed at any rate two results of prime
importance in the study of Nature Mysticism. The one is that
the air has furnished the primary type of the soul as the
principle of life--man's fleeting breath has suggested and
fostered the idea of immortality; the wind that bloweth where it
listeth, the idea of a realm of changeless spirit! The other result
is that certain of nature's most obvious phenomena, when seized
by intuition, can supply a key to some of her profoundest
secrets. Shall not these results be as true for the world of to-day
as for the flourishing times of old-world Miletus?