h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

You certainly can't declare yourself a real athiest and someone else not. You claim to be an atheist, so do they. You are both real. I usually see this in the arena of someone not being a "True Christian," but the idea is universal.

As for this idea that an ethical system can not coexist with "real" atheism, I would point you to the concept of enlightened self-interest. I wish to survive. Why? Does any other animal need a reason? No. I simply wish to continue living. It is hardwired into my nature. Based on that, my ethical system is based on how I can best survive. So, if someone has something I want, I could indeed kill them for it. But, someone could also then kill me to get the same thing. I don't wish to die. By extension, I can assume most of my fellows don't wish to die, either. Therefore, we must reach an agreement not to kill each other for the things we want. I don't get what I want, but I do preserve something I have already.

All our rights are extensions of that, things we want or things we already have that we want to protect from others. In fact, most rules, if you look at how someone breaking them might hurt you, suddenly make sense. So, even if I disagree with the religion that says "Thou shall not kill," I don't disagree with the idea itself. It is to my advantage.

Further, not all animals fit the kill or be killed model. If you truly intend to look at us as animals, you must look at social animals as well. There's far more to being animals than just kill or be killed.

I propose to you in closing that atheism is not your narrow definition nor mine. Atheism is a lack of belief in gods, nothing else are we guarenteed to have in common. To say what is true and what is not for atheists beyond the absence of a deity belief is then attempting to insert one's own agenda upon others.