As you touch on later in your post, the term "atheist" is generally reserved for people.
When I say "how the word is actually used," what I'm talking about is that when we consider how we use the word when speaking about adults who have put some thought into the issue of gods, we end up with a definition that also implies that babies are atheists.
"Atheist" doesn't indicate belief or disbelief. The only necessary qualification to be an atheist is that the person doesn't believe in any gods.
It really isn't that hard to manage. It's the exact same process we use to define words like "civilian" ("someone who isn't in the military"), "vegetarian" ("someone who doesn't eat meat"), "non-smoker" ("someone who doesn't smoke"), and many other terms.
For instance, some adult civilians may be civilians because they considered a career in the military and decided to do something else. Some may be civilians because they conscientiously object to military service. But when we hear a news report about, say, a battle that killed 50 civilians including 10 babies, nobody goes "hang on - a baby can't decide whether to serve in the military! They can't be civilians!" or "wait a minute - cats aren't in the military; how many of those civilians were cats?"
Except when we're talking about adult atheists, we apply the label in a way that just means "a person who doesn't believe in any gods." Even a baby is capable of doing that.
It's not that I want to; it's that I recognize that this is how the word is defined.
We wouldn't use the word, no. Just as if there were no military service, meat-eating, or smoking, we wouldn't have words to describe people who didn't do those things.
I'm saying that there's no single "concept of god." Instead, there are uncountably many different god-concepts, and no individual person is aware of all of them. It's impossible to simply reject all gods as a category, because the category is defined as a list of specific gods.
I'm insisting that we don't invent a special definition of the word "god" just to use in our definition of atheism. And in general use, there are no objective criteria for the definition of "god".
I've used this example before, but consider two divine messengers: Mercury/Hermes (a god) and the archangel Gabriel/Jibreel (explicitly not a god). What criteria could you possibly use to say why one is a god and the other isn't? Any objective criteria that you could come up with for what should and shouldn't be a god will either imply that the ancient Greeks and Romans were wrong to consider Mercury/Hermes a god (and maybe outright atheists, depending what your criteria are), or that modern Christians and Muslims are polytheists. Neither of these happens in real life; instead, our definition of "god" is generally based on whether people sincerely consider the thing in question to be a god... and that's it.
Tying this back to atheism: all of this means that rejecting every single god is practically impossible. It means we can't reject gods as a category, so to reject all gods, we would have to reject them one-by-one (or if we're lucky, specific pantheon by specific pantheon), which is beyond the capabilities of any person that the label "atheist" has ever been applied to.
Do you consider your cat (assuming he's male) a bachelor? After all, I assume he's not married, right?
I think it's bizarre when people invent problems with the normal definition of the word "atheist" but have no issue using words properly that are defined in a nearly-identical way.
... or maybe not so bizarre, since I think I see where it comes from. I see it flowing from stereotypes of atheists: to many people, atheists are nasty and bad, and babies are sweet and good, so to them, there's a conceptual mismatch when a baby is called an atheist.
But think about the process that an adult, intelligent atheist who has considered the issue of gods has gone through:
- he's probably considered arguments for god and rejected them... but rejecting an argument isn't the same as rejecting the conclusion of an argument. Intelligent people realize that true conclusions can be argued using crappy arguments, so the crappiness of an argument isn't an indication that the conclusion is necessarily false.
- he's probably encountered arguments that he couldn't even consider: maybe some were expressed badly, maybe they were in languages he didn't speak, but for whatever reason, he's probably aware that arguments for gods exist that he hasn't explicitly rejected as false.
- he's probably identified a few gods that are unfalsifiable... which means that he can't rationally reject them. All he can do is note that there's no justification for accepting them.
- he hasn't come close to even hearing about every god, so he certainly can't have rejected gods in general.
- he might think that people who believe in the gods he's considered are unjustified or foolish, but opinions about believers in gods are not beliefs about gods.
All in all, the criteria we use to identify an adult as an atheist also imply that babies are atheists. Personally, I don't really care in and of itself whether babies are atheists, but when people argue for a definition that implies babies aren't atheists, this implies they're arguing for a different definition than the one we use for adults.
At best, it's because they haven't thought about the issue too deeply (e.g. they only define "god" in terms of the specific god they believe in, and rejection of that god is something that a person could potentially be capable of); at worst, they're trying to paint atheists as unreasonable (e.g. trying to portray atheists as closed-minded by implying that they've prejudicially rejected concepts before they even heard them).
So that's why the question of whether babies are atheists matters.
