Well, because morality is normative: it instructs and favours. When I sense that an act is morally wrong it appears to me that the act is in some way 'not to be done' - it is as if the universe itself wishes me not to do it. Furthermore, it seems that the very existence of this kind of external instruction confers a reason to abide, regardless of any desires or interests I may have. I do not think I am unusual in having such impressions, for these features of morality are well attested to. Its 'normativity' is, I think a conceptual truth and many would say - and I'm inclined to agree - that is rational authority is as well. In other words, part of what makes a moral norm a moral norm is precisely the fact it is one that confers a reason for compliance regardless of any of our interests.
Now, perhaps we are all just suffering some kind of hallucination when we sense that some acts are right and others wrong. Perhaps there is no rightness or wrongness out there in reality. But most of us have the impression that rightness and wrongness exist. And it is hard - hard for me, anyway - to make sense of how such features could really exist unless a god exists. This is not to say that a god exists, just that morality - if it is to be real - requires a god.
Because I think morality is real, this raises a doubt about atheism.
Now, perhaps we are all just suffering some kind of hallucination when we sense that some acts are right and others wrong. Perhaps there is no rightness or wrongness out there in reality. But most of us have the impression that rightness and wrongness exist. And it is hard - hard for me, anyway - to make sense of how such features could really exist unless a god exists. This is not to say that a god exists, just that morality - if it is to be real - requires a god.
Because I think morality is real, this raises a doubt about atheism.
