Atheists; what do you base your morals on?

[Darkstar]

I agree. Which is why we can't define morals simply through empathy and logic even if it's our prime reliance in most morals.

Altruism? Maybe, as there is evidence of inherant altruism as being a part of "human nature" to some extent, but it does seem that there is something else to take into account. We have empathy, altruism, reason, and fear of punishment, (though the last really just prevents immoral actions, rather than directly supporting moral ones, and altrusim, if applied indescriminately, can be immoral in some cases, such as helping terrorists, though I guess the same could be said of empathy. Hence, reason...but if you know right from wrong and just don't care...).
There could be something else I am not thinking of...