A common theme throughout the definitions on this page is the primary use of "disbelieve" when defining atheism. Some modern dictionaries drop this, but most comprehensive dictionaries do not. For some reason, however, people simply ignore this word and move right along to the secondary sense of "denial." When we take a closer look at the word "disbelieve," however, we find two senses: an active and a passive.
In the passive sense, "disbelieve" simply means "not believe" thus a person who disbelieves a claim may simply not accept the truth of the claim without going any further, like asserting the opposite. In the active sense, "disbelieve" involves deliberately refusing to believe something (possible reasons might include a lack of evidence or an incoherent claim). In the active sense, "disbelieve" involves deliberately refusing to believe something (possible reasons might include a lack of evidence or an incoherent claim).
Definition of Atheism in Mid 20th Century Dictionaries:
Webster's Encyclopedic Dictionary, 1942.
- atheism [Gr. atheos, an atheist a, priv. and theos, God] The disbelief of the existence of a God or Supreme intelligent Being.
- agnostic [Gr. agnostos, unknowing, unknown, from a, priv. and gignosko, knowing. Same root as know] One of those persons who disclaim any knowledge of God or of the origin of the universe or of anything but material phenomena, holding that with regard to such matters nothing can be known.
- disbelief: Refusal of credit or faith; denial of belief; unbelief; infidelity; scepticism.
- unbelief: Incredulity; the withholding of belief; infidelity; disbelief of divine revelation; disbelief of the truths of the gospel.
Like some definitions, the above entry for disbelief leaves off the passive sense, defining it solely as an active refusal to believe something. Although this fails to account for the broadest sense of atheism, it nevertheless points towards atheism being broader than mere denial of gods generally or some particular God.
Webster's New Twentieth Century Dictionary, 1943.
- atheism [Gr. atheos, a, priv. and theos, God] The disbelief of the existence of a God, or supreme intelligent Being.
- agnosticism [Gr. agnostos, unknowing, unknown, from a, priv. and gignosko, knowing.] In theology, the doctrine that God is unknown and unknowable; because God has not revealed himself to man; because finite mind cannot comprehend God; because Absolute God cannot come into intimacy nor make himself known to finite mind. In philosophy, the doctrine that First Cause and the essential nature of things are unknowable to man; that it is impossible to know the existence of the human soul and Ultimate Cause, or to prove or disprove it.
- By agnosticism, I understand a theory of things which abstains from either affirming or denying the existence of God; all it undertakes to affirm is, that , upon existing evidence, the being of God is unknown. G.J. Romanes.
- disbelieve: Not to believe; to hold not to be true or not to exist; to refuse to credit.
The Winston Dictionary, 1943.
- atheism disbelief in, or denial of, the existence of God.
- agnostic one who denies that man konws the final nature of things; one who neither affirms nor denies the existence of God; adj. denying all certain knowledge of God or of the essential nature of things.
- disbelief: lack of belief or trust; denial of a creed. Synonym: unbelief, incredulity.
- disbelieve: v.t. to refuse to accept as true; v.i. to refuse to believe a statement, doctrine, etc.
- incredulity: refusal or inability to believe; disbelief; skepticism.
- unbelief: lack of positive faith or belief; especially, nonacceptance of the teachings of revealed religion.
- unbeliever: one who lacks faith; a doubter; especially, one who does not accept the teachings of any revealed religions.
Funk & Wagnalls New Standard Dictionary of the English Language, 1947.
- atheism: The denial of or disbelief in God, as a First Cause, or Ground, of the universe. As dogmatic atheism it denies, as negative atheism it does not believe in, and as critical or skeptical atheism (or agnosticism) it doubts, the existence of god.
- What is called positive or dogmatic atheism, so far from being the only type of atheism, is the rarest of all kinds. . . . Every man is an atheist who does not believe that there is a God. R. FLINT Agnosticism sec. 3, p. 53. [s. '03]
- Theism affirms, Atheism denies, Agnosticism ignores, the existence of any such soul. WAINWRIGHT Sophisms p. 247. [F. & W. 1883]
The above definition is among the most comprehensive because it very specifically acknowledges the three general positions an atheist might have towards gods: outright denial, active refusal to believe, and passive nonbelief. It still conflates agnosticism with a position independent of theism, but it observes more nuances than most dictionaries.

