"Society does. Different cultures have determined what they call morality or standards of right conduct." -Go
There are a few typical philosophical arguments against the view that society is the main determinant of morality. I'll mention 3:
1) The first criticism comes by way of "counter arguments". Hitler's 3rd Reich for example, dictated that it was morally required to get jews executed in gas chambers. If society determines morality (and each "society" is morally equivalent), then the implication of your view is that Hitler's actions were justified because that's what society was dictating at the time. Most people probably wouldn't agree with that view.
2) If the particular society you belong to is always correct in determining morality, then it follows that it's always wrong to criticize that society. I like to think that society isn't always right and is far from perfect. It seems revolutionaries like Jesus, Martin Luther King Jr. and other social reformers would agree.
3) The major argument against this view is difficulties in defining society. What exactly does "society" constitute? What happens if I happen to be bi-racial and belong to 2 different cultures/societies, who's rules do I follow if the two cultures happen to have contradictory views?
- If you think that even one of the above criticisms holds water, than you're forced to reject the idea that society determines morality... or at the very least you'd have to revise it.
- I would think that to some extent, society does play a role in what we consider good and evilů but it's certainly not the only criterion (as has been demonstrated by these age old criticisms)