Chapter 2: On the atoms

1. The philosophers call by the name of atoms certain parts of bodies in the universe so very minute that they do not appear to the sight, nor admit of τομή, that is, division, whence they are called atoms. These are said to flit through the void of the whole universe with restless motions, and to move hither and thither like the finest dust that is seen when the rays of the sun pour through the windows. From these certain philosophers of the heathen have thought that trees are produced, and herbs and all fruits, and fire and water, and all things are made out of them.

2. Atoms exist either in a body, or in time, or in number, or in the letters. In a body as a stone. You divide it into parts, and the parts themselves you divide into grains like the sands, and again you divide the very grains of sand into the finest dust, until if you could, you would come to some little particle which is now [such] that it cannot be divided or cut. This is an atom in a body.

3. In time, the atom is thus understood: you divide a year, for example, into months, the months into days, the days into hours, the parts of the hours still admit of division, until you come to such an instant of time and fragment of a moment as it were, that it cannot be lengthened by any little bit and therefore it cannot be divided. This is the atom of time.

4. In numbers, as for example, eight is divided into fours, again four into twos, then two into ones. One is an atom because it is indivisible. So also in case of the letters. For you divide a speech into words, words into syllables, the syllable into letters. The letter, the smallest part, is the atom and cannot be divided. The atom is therefore what cannot be divided, like the point in geometry....