I completely understand and support your view. I have heard many people claim that atheism is more logical or scientific than agnosticism but based on your definitions and others I've seen it seems to me that atheism is as based on logical galaxy than religion because it equates absence of proof with proof of absence.
On the other hand, because of the roots it could be argued that atheism opposes the worship of something that can't be proven to exist, although that might be antitheism. Regardless, as you said it's still semantics.
As a writer I value the precision of communication but usage is where words are truly defined. I agree that labels limit all of us a well. I think taking the time to know individuals and their ideas rather than defining them as a group would not only foster greater communication here but with those who practice religion as well.

"but in my mind these two concepts contradict. How can you both not believe (disbelieve) and claim unknowability?"
Easily, you do it too.
Do you believe you'll be dead in 30 minutes time?
I'd assume the answer is no.
Can you know right now that you won't be dead in 30 minutes time?
No.
So it's not at all contradictory to disbelieve something while simultaneous accepting you can't know it.

The difference for me has always been a belief/knowledge issue. In a technical sense everyone is agnostic, there is no way to fully know anything. Atheists In my opinion do not put forward a a disbelief or a belief that God is not real, just no positive belief that God is real. Your dictionary definition gets confusing because it describes atheists in 2 different ways. At first it's described as a lack of belief or strong disbelief, the later describes atheism as a belief that there is no God. The strong disbelief corresponds with the second definition, but what I think is more valid would be the "lack of belief" statement. I think atheists are "a theists" or without theology. Doesn't mean they believe a theology is wrong, does mean they haven't been convinced it's correct. Like in court, the options are not guilty or innocent, they are guilty or not guilty. That means either, HE DID IT, or THERE IS NOT SUFFICIENT EVIDENCE TO BELIEVE HE DID IT, and the whole time without asserting that he didn't do it.

"blurb". Hahaha!

Coincidentally...I have just watched this YouTuber, Rationality Rules, addressing David Mitchell's insistence that he is not an atheist - while claiming to be, the more rational, agnostic. David Mitchell is a very well known UK comedian. The YouTuber, Rationality Rules, is unknown to me until this video popped into my recommended list as I was browsing for funny David Mitchell skits. But Rationality Rules argued his case well.

Jump to about 4min and 25secs in this video:

Rationality Rules rationalises that:
"Theism and Atheism address what you believe. Gnosticism and Agnosticism address what you assert to know."

He makes an example addressing David Mitchell directly: "...If I ask you if you believe in a god, and your answer is 'no', then you're an Atheist. And if you answered 'I don't know', then you haven't answered the question. Either you believe or do not believe. That is, either you're a theist or an atheist. And how certain you are in your belief, that is: how Gnostic or Agnostic you are, is a completely different question. And so since you don't believe in a god or gods, you are an Atheist..."

From his rationale, Atheism and Agnosticism are mutually INCLUSIVE because I can be any of these:
a: a non-believer because there's no proof yet of existence of a god - an Agnostic Atheist
b: a non-believer because I know there's no proof - a Gnostic Atheist
c: a believer because there's no proof yet of non-existence of a god - an Agnostic Theist
d: a believer because I know there's proof of a god. (I hear his voice every morning.) - a Gnostic Theist

Theism/atheism is an answer to "Do you believe?" And Gnosticism/Agnosticism is an answer to "How certain are you of that belief?"

Just another bee in the bonnet.

I like simplicity, and it is really simple to look at the prefix and root words.

a- means without

-gnostic comes from the word gnosis, meaning knowledge.

-theism is the belief in a god or gods

Simply an agnostic knows of no gods (but might believe, given proof, or as pointed out might believe but not "KNOW" God) while an atheist believes there is(are) no god(s). That lines up with the definition that Webster so kindly published.

I always thought that an atheist didn't believe in god, and an agnostic doubted the existence of god but was still open to the possibility of god existing. Anyone else thought this?

Best rant ever silvereyes. I've read up on this and found an article by a guy defining a true agnostic. His beef with militant athiest was simple--I don't know if there is or is not a god, and I'm fine with admitting I DON'T KNOW. To him, the beauty of being agnostic is to be able to admit "I don't know the answer." Too many people insist on being right, both in the theist and atheist world. I agreed with his essay 100%. If you don't have evidence, don't pretend to know the answer. I don't know, so I am open to the possibility of a higher power. That power has not revealed itself to me as of this post, so I can't say for certain if there is one.

In logic and probability theory, two events (or propositions) are mutually exclusive or disjoint if they cannot both occur (be true). A clear example is the set of outcomes of a single coin toss, which can result in either heads or tails, but not both.
Mutual exclusivity - Wikipedia

For those who say the two are not mutually exclusive, you cannot say with certainty that there is no god and leave the door open to the possibility that one could exist at the same time, but at present there is no evidence.

I find the agnostic view the most open minded.

@silvereyes I totally agree with you. Do not like labels. Conflicted between atheist and agnostic myself. Freethinker seems to be an umbrella term. I think I'll continue to use freethinker.

Thank you, silvereyes, you show your depth in your posts. I think I use, Agnostic, because there are so many believers around me of different denominations. As you stated so well, the ultimate reality is unknowable. In other words, I DON'T KNOW! I know that there are believers out there that insist there IS no doubt about the existence of God/god(s) in the positive. An acquaintance once asked whether I was willing to believe in a god, and I answered, "It depends on what day of the week and what mood I'm in." As I have stated in another post, god could be a far more technologically advanced society or a group of experimental lab technicians.

I had a melt down from that last debate (a lot to process), and my brain is still a little soft, but I am still comfortable with agnostic. I still take at face value how ever folks want to identify them selves.

I find my self often having to define both terms. I gets quite tiresome. The only time I bother with this is when theist make statements like "atheist belive in God the just deny it" or "You can't be agnostic and atheist". Then I have to "school them". With knowlege comes understanding, with understanding comes tolerence.

Important topic. Thanks for putting the time into that. If you believe that the abrahamic god is real, clearly you cannot be either agnostic or atheist. If you beleive that the abrahamic god is definitely a fiction, you can't be agnostic. If you are open to the idea that some as yet undiscovered divine creator being might exist, you cannot be an atheist. That is why I think I might prefer the term antitheist for myself. See the definition of antitheism and see if it fits your situation. I'd be interested in hearing your thoughts.

An agnostic is essentially a "weak" atheist by definition. I consider myself an atheist/agnostic in that I, 1) have no belief in any god(s) and, 2) I see no evidence either way.

It's funny, in my brief time on this site, my awareness has also been broadened, but I've come to the opposite conclusion as you, @silvereyes. I have considered myself to be an atheist, but this site has shown me that I am an agnostic atheist. I don't know if there is/are (a) god(s), but until solid evidence is presented, l choose to believe god(s) do(es) not exist.

It is precisely because the two words are so different in meaning that I find them to not be mutually exclusive. And l will admit l was quite surprised to learn this about myself.

And while I agree that saying fuck the labels and get to know the person is a great attitude, labels are unavoidable. And given that, l feel that we should do our best to use them as valid descriptors of ourselves, just not as end all, be all definitions.

Thanks for such a thoughtful post.

I regard [a]gnosticism as a knowledge position and [a]theism as a belief position. My knowledge position is agnostic -- I don't claim to know with absolute certainty that there are no gods. And my belief position is atheistic -- I don't see a valid reason to believe in any god.

Classic Huxlian agnosticism IS as you describe it ... the notion that not only do I not personally stake a knowledge claim one way or the other -- but that it's not even doable. I hold to this, because invisible beings allegedly outside the natural order are inherently non-falsifiable.

However, many modern agnostics are "soft" agnostics who just profess to be personally "not sure", implying that some new information could change that in the future. What information that might be, they never seem to say. i think this latter, watered-down agnosticism is responsible for the notion that agnosticism is some sort of way-station between belief and unbelief. Theists find this idea pleasing because uncertainty is far less threatening and taboo than unbelief, and besides, such an agnostic might still be persuadable. They tend to consider atheism too irredeemable to hold out the hope of [re]conversion.

Another major reason for "agnostic atheism" is that it circumvents the argument that atheism is inherently "arrogant". If atheism claims to KNOW there is no god, that argument finds some purchase, because you'd have to be god yourself -- be everywhere and everywhen -- to LITERALLY stake such a knowledge claim. And fundamentalists are nothing if not literal. I am willing to not KNOW there is no god, even if on a technicality, to emphasize that atheism is really a different beast: not affording belief to the unsubstantiated and/or highly unlikely.

To me, "there is no god" is a semantic shortcut that would be reasonable in any other discussion but this one. I live my life exactly as if I were making such a knowledge claim. The difference between being 100% sure and 99.9999% sure isn't a practical difference. But I'll be damned (ha!) if I'm going to give a believer an excuse to dismiss a considered, substantial certainty with mere arrogance.

Yes there is a creator, modern man calls her nature, her and the big bang is what led to our creation.

Short version of my long answer is...It's usually agnostics who quibble about such bullshit. You know what you are. Any one trying to tell you what you are is an asshole so fuck em, I say. Now at the risk of being an asshole myself I 'm going to label you a pretty cool person. The kind I like. wink wink.

All true I would say, but for prefixes being a cause of the confusion. The "confusion" lay in religious indoctrinators defining the words to suit their own purposes and disseminating them. This is why people get the question "Do you worship the Devil?" I dare say very few ever came up with such nonsense on their own.

What would one call a person who does believe in a "prime source" but is determined to, come judgement day, insist that that entity be judged because of the evil it has perpetrated upon humanity. One might say this person hates "god". And do not reply that this woudl be satan worship since satan is a made up being , just as all the gods ever dreamed up.
My belief is that there is/was an entity that created everything, including cancer, malaria, dementia and every evil that can befall mankind , alzheimer's being the worst of all, and that this entity must be held accountable for it's atrocity. I know this is not atheism nor agnosticism , just wondering.

Fantastic post! Thanks for sharing, I really enjoyed your efforts to educate us with cited sources. I find myself in conflict with fellow agnostics/atheists on many levels. I reject the dogma, I reject the required conformity of religion, but I do believe in the concept of a soul. Not as a religious concept, but as a scientific construct. I often find myself with non religious people who don't believe in anything that is currently termed "supernatural". But I continue to study, research, and strive to find truth in the "mind" being an entity beyond the physical brain. I am looking for evidence out of a deep seated belief, whether real or imagined that we are more than our physical body. But I am coming at it from a scientific approach, not theological.

I really enjoyed your post. I have bit of a different take on it, though. Let me know if you have thoughts.
I'm not particular on what someone calls themselves, I know atheist has negative connotations associated with it and I can see why people avoid it. However, I think the confusion is that theism and gnosticism address two separate prongs of the question and that's what is getting mixed together.
Theism is a belief in god/s. Atheism is lack of belief in god/s.
Gnosticism is a claim of knowledge about something. Agnosticism is claim of lack of knowledge of something.
Essentially one is dealing with belief, and the other is dealing with claiming knowledge. You can believe there is god/s and claim to know for sure. You can also believe in god/s and claim not to know for sure. You can disbelieve and claim to know for sure, or disbelieve and claim not to know. They are separate questions.
The confusion is that both positions are binary. As you state you don't believe in any god/s. Then you say you don't disbelieve. These are contradictory statements. You can say you hold no belief either way, but that in fact makes you an atheist because you have to have a belief to be a theist. And if you are not a theist, you are by definition an atheist. Now if you want to call yourself something else, that is perfectly fine. None the less, unless you believe it, you are not a theist.
Same goes for gnosticism. You either claim to know or you don't. If you don't claim to know you can't then say but I don't claim not to know. You either do your you don't.
The difficulty, and where I feel this is important, is that claims of existence are by their nature unfalsifiable. Take the statement "fairies exist." Now you cannot prove that fairies don't exist anywhere in the Cosmos. However, currently we don't have any good evidence that they do exist. At some point we might have proof they exist, but we will never be able to prove that they don't or cannot exist. Now the question is do you believe they exist? I'm guessing you don't.
It's the same proposition for god/s, dragons, unicorns, people, gravity, and anything else you can claim exists. The difference is we have proof of things like people and gravity existing and no good proof for god/s, dragons, or unicorns.
This is why I think god claims are ridiculous, because we can make anything up and claim it exists and nobody will ever be able to falsify that claim. But just because you can't disprove something doesn't add an ounce of truth to the claim.
Why it's important to understand the difference is that people act on their beliefs based on what they claim to know. And this is how people can justify burning witches; racism; slavery; and a lot of other horrible things based on unsubstantiated beliefs.
What I don't like about the term agnostic has nothing to do with those who call themselves that, but how it gets used against those who don't believe. Because it's how religions use the term to make the claim that belief and disbelief are on equal footing because you don't know for sure either way. When in fact they;re not. Religions are making claims to know god/s and what they want us to do, and what will happen to us if they don't, as where atheists are just saying "I don't believe you." Atheists aren't making the claim so they don't have burden to prove it false. Theist are responsible for proving their claim is true, otherwise how do we know they didn't just make it up. However, if you're a theist who doesn't claim to know for sure if there is a god/s and what they may or may not want or do and generally have a live and let live policy for others then I don't have a problem with you. I just think you believe for bad reasons.
I think the confusion here is that atheism gets branded as if we are claiming there are no god/s, when that is not the case for most atheists. And for those that claim that, that is something they would have to prove, and you can't definitively prove a negative.
Thanks again for the post, it was very thought provoking.

What do you atheists not believe in? "God"? What the dickens is that? What do you agnostics withhold judgment on the existence of? "God"? What the dickens is that? An infinite omnipresent incorporeal spirit that created everything but the infinite omnipresent spirit that created everything but itself? What the dickens is that?

Great rant! Occasionally I wonder if I'm actually agnostic, but saying atheist simplifies it. People are not as likely to start in trying to convince me that their religious argument will be the one that converts me. Plus, my agnosticism comes with some caveats. Such as if God is an asshole, I don't believe he is worth worshipping or in other words he or it may exist, but maybe i don't "believe in" him anyway. Also I do believe in something love-driven that we all are accountable to. I don't necessarily believe that this thing is sentient, judging, or controlling, so, not exactly God. I believe that when you love someone and they love you, something survives after death that can be of great comfort to the survivor. The degree of "real" as opposed to seeing what we want to see is unknown to me, but I lean heavily toward the latter. Doesn't mean if I become widowed I won't indulge myself with the sense of comfort a "sign" from my husband would bring. What does this make me? I'm comfortable with the label "atheist" and certainly "skeptic". I don't believe that bad things come in threes or that my black cat will ever bring me bad luck. I don't believe I can just up and manifest anything I desire. But I also understand that being open to the "magical" in life enriches the experience. To each her own but finding my "tribe" of like-thinkers makes life a little sweeter. Like-thinkers don't have to think exactly alike or agree on every definition.

Look for a book called Atheism: The Case Against God, by George H. Smith. Read the first chapter where he defines atheism and variants of it, as well as agnosticism. It is beautifully simple, jarringly simple, but very important. And you will know why there are still some hotly contested discussions among non-believers. Don't rant about it. Figure out why.