• we don’t believe humans have a soul, therefore
• we think this life is all there is – there is no afterlife, therefore
• we think that there is no reward (eternal heaven) or punishment (hell) awaiting us after we die, therefore
• we have no motivation to be good people – we have no good reason to be good and will act in only self-serving ways.

Some might be surprised to learn that I, and many of my atheist brothers and sisters, care more about treating people with care and respect now than we did before becoming atheists. Why? Well, because:

• we don’t think humans have a soul, therefore
• we don’t think there is an afterlife, therefore
• we think this life is all any of us get, and
• we want this life to be as happy and fulfilling as possible, and
• we think every human deserves to have what we have.

Those last three bullets are all about having a heightened sense of empathy around human desires to avoid suffering and be happy.

But what underlies this empathy for another’s happiness? Although I can’t speak for all atheists, I’ve read enough blog posts, comments and forum threads to have seen a consistent answer from many of us, and I’m guessing it boils down to this line of reasoning:

• we share a sense of wonder and awe that our 14 billion year old universe and 4.5 billion year old earth yielded life
• because of this multi-billion year heritage, we also share a deep-seated feeling of interconnectedness – via shared ancestry – with all of earth’s living creatures
• we have an intense appreciation for the struggle to survive among every human – past and present – along with the notion that we are all related
• we are exquisitely grateful for the good fortune of being part of the chain of life
• we share a sense of kinship, care and respect for others within that chain

Evolutionary biologists often theorize that caring and morality are evolved, built-in characteristics of human beings (I’d guess they are right). That’s one way of explaining how we came to care. What I’ve tried to do above is slightly different – I’ve attempted to put a more personal face on why we might care.