Conflated and Misunderstood Terms terms atheist science morality belief

Is there any difference between does not believe and lack of belief? The statements CAN be used interchangeably but is there any nuance to the terms? Are there times where we could use lack of belief but not does not believe?

To be sure we are on the same page, we should start by defining our terms.

What is a Belief?

There are a few definitions of belief, but they are all essentially saying the same thing.

  • Something accepted as true
  • Something thought most likely/probable
  • Something concluded is the case
  • A positive attitude towards a proposition
  • Strong trust or confidence in something

So, whether you think your friend will do well in an exam, you’ve looked at evidence and come to a conclusion, been convinced something is most likely the case, or think a proposition seems probable, they are all different ways of describing belief.

Watch this video on YouTube.

Does Not Believe

When someone does not believe something or says, “I do not believe [this]” they are talking about something they have considered. Even if that consideration is a for a split second.

The thought “I do not believe [this]” cannot cross one’s mind without being aware of what [this] is. Usually, we would think if someone does not believe [this], it is because they think [this] is false, however, this is not always the case.

The person might be ambiguously/inaccurately describing their whole position.  They could be unsure if [this] is true or false, so, rather than a state of disbelief they are suspending judgement.

Not is a word used to mean negation or the opposite of. Consider atypical as not typical. (yes, the a-prefix can sometimes mean without as well, and it is from the context we learn which.)

Lack of Belief

Whilst there are some who use lack in the same way as does not, usually due to the rational ‘if I do not hold a belief I lack a belief’ the term holds a different meaning. 

Lack is usually used to mean without or to not have enough of. The latter isn’t really how someone would describe a belief state “I don’t have enough belief in [this]” so we can infer they mean without. 

If we consider atypical again “without typical” doesn’t really make sense, so we can assume Not and Without are different.

Without is synonymous with absence.

Lack of Belief: Absence

To be truly absent of a psychological state in regards to [this] you would have to be totally unaware of [this]. Therefore, for anything you are aware of you can’t actually totally be absent of a psychological state relating to it.

You can, however, be absent of a specific psychological state relating to it and what is meant is lacking the psychological state “belief in [this].”

This might sound the same as the previous, don’t believe, but there is a key difference.

Lacking a psychological state

If you are just describing a psychological state that is absent then not only could this include babies, which we’ve already shown to be problematic, but also can be taken to an absurd level where we include things like; apes, dogs, cats, ants, cucumbers and even rocks.

This might sound like an absurdum, but there are folks that genuinely do make these claims.  At least they are consistent and seem to understand what is actually meant by lacking belief, even if it has lead them to absurd claims.

This is one of many of the Definitional Problems with Lacking Belief.

Lack of Belief vs Does Not Believe


  • When one does not believe something, they are talking about a considered response to something they are aware of. It is a response to some form of content.
  • Lacking belief is purely describing an absent psychological state.
  • Its generally clear what is meant by does not believe even if there is ambiguity over what one DOES believe.
  • Lacking belief is used in a variety of ways and none are particularly clear.


  • Neither response is fully answering a proposition.
  • Therefore, there is some ambiguity.

Answersing a Proposition?

A proposition is a bivalent truth-apt statement – that means it can be TRUE or FALSE (not both)

Example: It is raining outside my house right now.

Questions are not propositions but propositional content can be added to a question.

Example: Is it raining outside my house right now?

Both can be answered the same way.

When answering a proposition, you are supposed to answer whether you think TRUE and whether you think it FALSE. Saying you don’t believe a proposition is only saying you don’t think it is true, although it should also mean you think it is false. 


  • Is it raining Outside?
  • I don’t believe it is raining outside. 

Lacking belief in a proposition doesn’t even make sense.


  • Is it raining outside?
  • I lack belief it is raining outside.

If we are honest, neither of these actually seem to be answering that question, so how should we answer it?

How should we answer a proposition?

There are 3 epistemic answers to a proposition that completely answer it

  • If you conclude the proposition is true, you are affirming the proposition, answering YES, meaning you BELIEVE it. (This entails not believing it false)
  • If you conclude the proposition is false, you are denying the proposition, answering NO, meaning you DISBELIEVE it. (This entails not believing it true)
  • If you are unsure and cannot come to a conclusion, you are SUSPENDING JUDGEMENT.
    (This entails not believing it is true and not believing it is false) •Both disbelief and suspense of judgement entail not believing the proposition is true.

For a more in-depth look, check: You won’t believe this… (Logic and Belief)

There are also other indirect answers that entail a form of lacking belief.

Along with the 3 answers, there are in fact 2 answers that are even firmer versions of belief and disbelief known as denial and confirmation.

Below there is a table to shows these positions and entailments.

Not Quite Answering the Proposition: Does not believe & lack of belief

When you say “I don’t believe X” you’re not fully answering the proposition, but you are giving a considered response to the proposition, or at least propositional content within a belief.

We have no clue if you think it is false or are suspending judgement. It does entail a lack of a belief in X though. 

Lacking a belief is slightly different. It is describing an absence of a psychological state. Lacking belief god exists is describing “I lack the psychological state ‘God Exists is True’” – which is why lack of belief definition is open to being extended to ABSURD levels like “Rocks are atheist” 

As the response “I don’t believe X” isn’t a full answer to the proposition it changes the way it looks like so:

In Summary of Propositions and Mental States

  • If we consider a proposition we think false, that means we believe it to be false.
  • Believing something false entails not believing it true which in turn entails lacking (or an absence of) the psychological state of believing it true.
  • Not believing something is a response to belief (or propositional) content that entails an absence of acceptance to that content.
  • Simply not believing something doesn’t necessarily mean you believe it false though.
  • Lacking belief is just describing an absence of a psychological state, it doesn’t necessarily entail a response to propositional content.
  • So, if someone is unaware of a proposition, they would lack a psychological state in regards to it.
  • Equally if someone doesn’t care enough to give a proposition much thought we could conclude they lack belief too, as they are also not responding to the content directly.
  • Whereas someone could consider a proposition and be uncertain in their evaluation, therefore they would not believe it true or false (which would entail lacking the belief either way) 
  • Ultimately, this distinction is probably one that not many consider. With people using the terminology so interchangeably it probably isn’t worth considering this difference too hard and getting them to stipulate what they mean.
  • The only other comment I have on this lack of belief use is, it’s not how people tend to converse about things they do not believe in. We don’t say I lack belief in flat earth, I lack belief your team will beat mine, I lack belief in Santa.
  • We would at the very least say don’t believe, if not reframe it as a belief in the opposite… So why with one topic in particular is lack of belief used?


  • Lacking belief and does not believe often get conflated, and whilst there are some similarities can be actually quite different.
  • Does not believe is a considered response and a read of an absent psychological state.
  • Lack of belief is a read of a psychological state that is absent.
  • Neither fully answer a proposition.
  • If you are consistent with the “lacking belief” response it leads you to absurd conclusions like babies, cucumbers and rocks are atheists.
  • Lacking belief is not the same as does not believe, though at times gets used the same way, and this lack of clarity can cause confusion.
  • Due to people using the terms interchangeably it is best to clarify exactly what they mean by the terms when they use them, rather than get in to a semantic battle.