The term “non-theist” already exists to denote individuals who merely lack belief in God.1 This is relevant for three reasons.
• First, re-defining atheism to refer to a “lack of belief” would make the term “non-theist” superfluous.
• Second, individuals wanting to efficiently communicate their position of disbelief in God have always been able to simply say “I'm an atheist” in the past, just as theists could always say “I'm a theist”. All who disbelieve in God and want to be open about their belief in discourse would now be required to say or write-out “positive atheism” and say “I'm a positive atheist”, which just seems awkward and unnecessarily burdensome given how frequently the term is used in some disciplines and conversations.2
• Third, it seems more appropriate to call babies, cats etc. “non-theists”, rather than “atheists”.3
In academic settings (peer review etc.), atheism is consistently understood as the belief that God does not exist.
• The Cambridge Dictionary of Philosophy: “[Atheism] denotes a belief that there is no God; this use has become the standard one.” Notice how it specifically excludes the non-theist definition as being standard.
• However, few dictionaries of philosophy even mention the non-standard “lack of belief” use, despite wide-spread use by some communities on the internet and YouTube. (This is presumably for the same reason most biology dictionaries do not mention definitions of evolution which include the origin of the Universe or first life—despite widespread use of this definition by Young Earth creationists online.)
• A few academic atheists have suggested changing the standard definition to mean non-theist, but to no avail.1, 2 Today still, “The theist is commonly regarded as one who believes theism; the atheist believes atheism.”3
This is relevant both for lay conversations using the term and for academic venues. Relevant for lay discussion: In most conversations about God's existence, the level of precision would benefit from reflecting academic discourse because the terminology as established has been established this way for a reason. (See above.)
Relevant for academics: In academic conversations about God, shifting the meaning would introduce new frustrations and confusion for academics. Students and professionals who are reading and quoting peer-reviewed material would need to be very sensitive to the sudden grand shift in meaning, and therefore to the dating of the source they are quoting. (Is this usage instance pre-shift or post-shift?) Likely necessary would be swaths of footnotes to elucide for readers the meaning of atheism as used in this or that quote.
Theism (as classically defined) and atheism are contradictories, such that if theism is true, then atheism is false (and vice versa).
• …atheism is defined in terms of theism (as its opposing view).
• …these terms are best seen as being about God's existence and not about a person's psychological state.
The revisionist “lack of belief” definition of atheism is overtly ambiguous.
(a) …affirming the proposition <God does not exist>, or…
(b) …withholding belief about it (traditionally called “agnosticism”).1
The Greek roots of “atheism” yield “not theism.”1
• ...the “a-” can be a negation instead of absence (“not” instead of “without”).2
• ...a words meaning is not bound up with its etymology.3
Several everyday people on the street understand “atheism” to denote a “lack of belief” in God.
• ...the fact that Matt (etc.) have to “correct” people so often says otherwise.
• ...even if that were true, lay internet users etc. commonly understand a term to mean something that it does not actually mean. For example, “schizophrenia” is commonly, and yet mistakenly, understood to refer to multiple personality disorder.1
There are dictionaries which include a definition of atheism that is synonymous with “lack of belief” in God.
• …Oxford Dictionary includes, “Disbelief or lack of belief in…”
• …Marriam-Webster includes, “a lack of belief or a strong disbelief in…”
• …any dictionary including both competing definitions does not establish one definition (lack of belief) over the other.
• …modern dictionaries are descriptivist; they merely catalogue ways people use words regardless of how inane the usage is. Their various (and competing) definitions are often intolerable in academic or serious contexts like philosophy where precision and utility rule.1