What does atomism mean?
Atomism is the doctrine that everything — matter, meaning, or society — can ultimately be broken down into small, indivisible units. Its oldest and most famous form comes from the ancient Greeks: Leucippus and his student Democritus taught in the fifth century BCE that reality consists of tiny indestructible particles, called "atoms," moving through empty space. This idea was revived during the seventeenth-century scientific revolution and helped lay the conceptual groundwork for modern chemistry and physics, even though today's physicists know atoms are themselves divisible. In the twentieth century, Bertrand Russell and Ludwig Wittgenstein developed "logical atomism," treating complex propositions as combinations of simpler atomic ones. Social theorists use "atomism" more critically, describing views that picture people as isolated individuals rather than members of communities. Formal in tone, the word belongs chiefly to philosophy, history of science, and social criticism, where it signals any worldview built from discrete parts rather than seamless wholes.
nounThe philosophical or scientific doctrine that reality consists of discrete, indivisible units called atoms, whether the physical atoms of matter or abstract indivisible elements of thought, society, or meaning.
- In philosophy: the ancient and early-modern doctrine that all reality is composed of tiny indivisible particles moving in a void (associated with Democritus, Leucippus, Epicurus, and later Gassendi).
- In science: the view that physical matter consists of discrete chemical atoms, now superseded by subatomic physics but historically foundational to chemistry and physics.
- In logic and philosophy of language: logical atomism, the analytic approach of Russell and Wittgenstein holding that propositions can be broken into atomic components corresponding to facts.
- In social theory: social atomism, the view that society is best understood as a collection of autonomous individuals rather than organic wholes.
"Democritus's atomism anticipated modern atomic theory by more than two millennia."
"Leibniz rejected Democritean atomism because indivisible material bodies seemed inconsistent with the infinite divisibility of space."
"Critics argue that market liberalism rests on a kind of social atomism that ignores the ties binding individuals into communities."
The plural is rare and appears only when contrasting distinct versions of the doctrine, typically across different philosophers or eras.
"Ancient and modern atomisms differ sharply on whether atoms possess inherent properties."
Two thousand years before scientists could see an atom, Greek philosophers argued their way to its existence purely by reasoning — and they were right.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of atomism
Atomism derives from "atom," which English borrowed in the late Middle Ages from Latin "atomus," itself taken from Greek "átomos" (ἄτομος), meaning "uncuttable" or "indivisible." The Greek word combines the negative prefix "a-" with "tomos," from the verb "temnein," "to cut." The suffix "-ism" marks it as a doctrine or system of belief, so atomism literally means "the doctrine of uncuttables." Cognates sharing this root include "atomic," "atomize," and "anatomy" (literally "cutting up"). The term for the philosophical doctrine entered scholarly English usage by the early modern period, as revived Greek atomism spread through Renaissance and seventeenth-century natural philosophy.
How atomism is actually used
"Atomism" is primarily a term of intellectual history and academic philosophy, so it carries a formal register; it appears rarely in everyday conversation. It is usually discussed with reference to a tradition or thinker ("Epicurean atomism," "Russell's logical atomism"). The word has no common adjectival form — writers instead use "atomistic" or "atomist" — so it should not be pressed into adjective slots.
Easily confused with atomism
Atomism is the doctrine or belief in atoms as fundamental units, while atomization is the process of breaking something into separate fragments or isolated parts.
Autism is a neurodevelopmental condition affecting communication and behavior; it shares no meaning with atomism despite a superficially similar spelling and rhythm.