science has since practically abandoned but which it may some day be
compelled to take up. The atoms of Democritus seem to us gross, even for
chemistry, and their quality would have to undergo great transformation
if they were to support intelligibly psychic being as well; but that
very grossness and false simplicity had its merits, and science must be
for ever grateful to the man who at its inception could so clearly
formulate its mechanical ideal. That the world is not so intelligible
as we could wish is not to be wondered at. In other respects also it
fails to respond to our ideals; yet our hope must be to find it more
propitious to the intellect as well as to all the arts in proportion as
we learn better how to live in it.

The atoms of what we call hydrogen or oxygen may well turn out to be
worlds, as the stars are which make atoms for astronomy. Their inner
organisation might be negligible on our rude plane of being; did it
disclose itself, however, it would be intelligible in its turn only if
constant parts and constant laws were discernible within each system. So
that while atomism at a given level may not be a final or metaphysical
truth, it will describe, on every level, the practical and efficacious
structure of the world. We owe to Democritus this ideal of practical
intelligibility; and he is accordingly an eternal spokesman of reason.
His system, long buried with other glories of the world, has been partly
revived; and although it cannot be verified in haste, for it represents
an ultimate ideal, every advance in science reconstitutes it in some
particular. Mechanism is not one principle of explanation among others.
In natural philosophy, where to explain means to discover origins,
transmutations, and laws, mechanism is explanation itself.

Heraclitus had the good fortune of having his physics absorbed by Plato.
It is a pity that Democritus' physics was not absorbed by Aristotle. For