Atheism itself, atheism as such, isn't and can't be a movement, because atheism is, at a minimum, simply non-theism: non-belief in any god. Mere non-belief in any X can't by itself constitute a movement, because it's merely an absence (or at most a refusal) of belief. If every absence of belief in [your chosen belief-object here] amounted to a movement, the traffic jam would be a nightmare. A belief about the world shouldn't necessarily commit us to political action – we have to be able to say "No" to affirmative beliefs about the world without thereby signing up to a campaign. We need to be able to make such choices more freely than such a requirement would allow.

Atheism can however include something like a movement, of course, as can other beliefs and non-beliefs. Some of the disagreement among atheists is around this issue. Many atheists want to be able to be atheists without being dragooned into some boring noisy unsubtle bad-tempered "movement". Many other atheists want to be able to be overt explicit unbashful atheists without constantly being told to be more euphemistic or evasive or respectful or just plain silent by other atheists, who surely ought to know better.

This "who surely ought to know better" is one place where the disagreement really grips. To the first group – let's call them plain atheists – this idea looks like typical political hegemonising, like ideological policing, like the demand for uniformity and agreement and loyalty that always goes with a "movement". It looks like groupthink. To the second group – call them movement atheists – that's not it, it's just that other atheists should understand that euphemism and respect have been the norm for a long time and we really ought to be allowed to talk freely.

I'm in the second group, but when I try hard enough, I can see why people in the first group want to be able to be atheists without taking on a whole lot of extra baggage.

The problem, of course, is that what each group wants is incompatible with what the other group wants. In a perfect world, plain atheists could just ignore movement atheists, and movement atheists could mutter away without disturbing their quieter friends. But in the real world, many plain atheists feel that movement atheists bring the whole notion of atheism into disrepute. We make it more difficult for plain atheists to be just that, because the world at large now thinks of atheists in general as movement atheists.

I see the difficulty, and like the walrus, I deeply sympathise, but I also think that plain atheists should to some extent put up with it. We don't actually want to dragoon them into "the movement" but we would like to be able to talk freely without even other atheists telling us to pipe down.

To put it another way, we're not telling them to be noisier, but we don't much like it when they tell us to be quieter. That seems reasonably fair, I think. Yes, granted, we've made it somewhat harder to be a plain atheist (though they could always just closet themselves completely, by pretending to be theists) – we seem to be jumping up and down on the parapet yelling "over here, we're over here!" while everyone else is trying to avoid enemy fire. But that's life. The pope is always making life difficult for liberal Catholics, too; so it goes.

Where one locates oneself on this map depends partly on whether one thinks religion is mostly benign, or mostly harmful, or a difficult-to-unravel mix of the two. It's not a neat mapping though – I'm a committed "movement" atheist in the sense that I really do think taboos on open discussion of religion should go away, but I also think religion is a difficult-to-unravel mix of the benign and the harmful. But then I wouldn't be surprised to learn that all "new" or movement atheists match that description too.