in Philosophy, a particle of matter, so minute, as to admit of no division. Atoms are the minima nature, and are conceived as the first principles or component parts of all physical magnitude.

ATOMICAL philosophy, or the doctrine of atoms, a system which, from the hypothesis that atoms are endued with gravity and motion, accounted for the origin and formation of things. This philosophy was first broached by Mochus, some time before the Trojan war; but was much cultivated and improved by Epicurus; whence it is denominated the Epicurean Philosophy. See Epicurean.