telligible 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 with the flux observed, and mechanism con-
