[ at-uh-miz-uh m ]
/ ˈæt əˌmɪz əm /


Also called atomic theory. Philosophy. the theory that minute, discrete, finite, and indivisible elements are the ultimate constituents of all matter.
Psychology. a method or theory that reduces all psychological phenomena to simple elements.

Origin of atomism

First recorded in 1670–80


at·om·ist, nounat·om·is·tic, at·om·is·ti·cal, adjectiveat·om·is·ti·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for atomistic

British Dictionary definitions for atomistic

/ (ˈætəˌmɪzəm) /


an ancient philosophical theory, developed by Democritus and expounded by Lucretius, that the ultimate constituents of the universe are atomsSee atom (def. 3)
  1. any of a number of theories that hold that some objects or phenomena can be explained as constructed out of a small number of distinct types of simple indivisible entities
  2. any theory that holds that an understanding of the parts is logically prior to an understanding of the wholeCompare holism (def. 3)
psychol the theory that experiences and mental states are composed of elementary units

Derived forms of atomism

atomist, noun, adjectiveatomistic or atomistical, adjectiveatomistically, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012