The ancient theory of Democritus, Epicurus, and Lucretius, according to which simple, minute, indivisible, and indestructible particles are the basic components of the entire universe.

• 原子论古哲学家德谟克利特、伊比鸠鲁、卢梭等所持的唯物主义理论，认为简单微小的、不可分割、不可消灭的微粒是整个宇宙的基本组成部分