atomic philosophy

Webster's Dictionary (1913)

or Doctrine of atoms, a system which, assuming that atoms are endued with gravity and motion, accounted thus for the origin and formation of all things. This philosophy was first broached by Leucippus, was developed by Democritus, and afterward improved by Epicurus, and hence is sometimes denominated the Epicurean philosophy.

From the entry Atomical.

Webster’s Revised Unabridged Dictionary (1913), from GCIDE 0.54