Methodological Naturalism and Morality Throughout philosophical history, morality has been talked about in terms such as "utterances of ought". Such things have been called "moral claims" due to the inclusion of "ought", and moral claims are claims based upon one's own moral thought and belief; one's own morality; one's own criterion - per se - of what counts as acceptable/unacceptable thought, belief, and/or behaviour.
We all know about Hume. For those who do not: Look up Hume's guillotine. Hume is perhaps best known for it. He convincingly argued that one cannot derive an ought from an is without presupposing another ought somewhere along the line. This basically put an end to such derivations being bandied about as if they are somehow logically convincing trains of thought, and helped give rise to the moral intuition vein of thinking common nowadays.
The issue pertains to what we're supposed to do when there are conflicting moralities; conflicting thought, belief, and/or ideas about what ought be done, about what we ought aspire towards. The issue is who is the ultimate arbiter; by what standard ought we decide what to do as a result of the conflicting ideas resulting from relative nature of all morality.
There can be no doubt that something must be done. That's not a matter of ought. What is a matter of ought, is which action ought be chosen, which kind of thinking ought be fostered, which beliefs ought be cultivated, and what standard we use to establish and/or determine this.