Morality is part of human nature, atheist or not, In order to live in this world you have to make choices that are due to your moral.
There is no real difference between atheist and theist, both believe in something (god or scientific realism).
It is true that an atheist that believe in the supremacy of science, because of the pictures science give us of the world, he should not bother of morals, because, the world is governed by amoral (i do not mean immoral) physical laws and any decision he will make is becaus of his gene and the environment but he also know that the morals he has been educated with has evolved from natural laws and if it has survived until now, it is probably good to use it.
In other words, while knowing that ultimately (in nature), there is no moral, he knows that in order to survive ha has better to follow one. He has better to believe in something ;-)
Remark: It is one reason religion are powerful: the belief in religion is fit (in evlutionary term) for organism to survive and reproduce in humans societies
If we can imagine someone without moral (I am not talking of a guy with a deviated moral that for example feel that killing is good instead of bad), I think he will be not recognizable as such (without moral) because he will still follow the physical laws, only inside himself he would be free from sorrow. I think it is what Krishna was trying to teach to Arjuna in the battlefield of the Mahabharata.
There is no real difference between atheist and theist, both believe in something (god or scientific realism).
It is true that an atheist that believe in the supremacy of science, because of the pictures science give us of the world, he should not bother of morals, because, the world is governed by amoral (i do not mean immoral) physical laws and any decision he will make is becaus of his gene and the environment but he also know that the morals he has been educated with has evolved from natural laws and if it has survived until now, it is probably good to use it.
In other words, while knowing that ultimately (in nature), there is no moral, he knows that in order to survive ha has better to follow one. He has better to believe in something ;-)
Remark: It is one reason religion are powerful: the belief in religion is fit (in evlutionary term) for organism to survive and reproduce in humans societies
If we can imagine someone without moral (I am not talking of a guy with a deviated moral that for example feel that killing is good instead of bad), I think he will be not recognizable as such (without moral) because he will still follow the physical laws, only inside himself he would be free from sorrow. I think it is what Krishna was trying to teach to Arjuna in the battlefield of the Mahabharata.