The second volume of Democritus deals with the achievements and contributions of the Atomists to the science of their time and includes all the excerpts and testimonies related to the fields of mathematics, geometry, stereometry, optics, astronomy, geography, seismology, and meteorology.

It also includes excerpts from diaries compiled by the Atomists based on their observations of solar, planetary, and astronomical phenomena.

Finally, within the volume, the pioneering views of the Atomists on the nature of time, space, and motion are developed. It is thus demonstrated, based on the ancient testimonies themselves, that the Atomists have been led by the very foundations of their theory to the conclusion that time, space, and motion must be perceived as composed of indivisible minimal quantities.

In an astonishing way, the most modern concepts of physics and cosmology come to agree with them!