The is-ought problem refers to whether claims about what ought to be can be made on the basis of statements about what is. Another way to put this is whether “ought-statements”, which express moral values about what is good in the world, can be derived from “is-statements”, which describe some aspect of the world. Resolution of the is-ought problem requires exploration of the relationship between ‘is’ and ‘ought’. Is there an insurmountable chasm between what exists – the world of facts, evidence, and scientific knowledge – and what ought to be – what values we should hold, what standards of right and wrong? Or might the ‘is’ influence (but not determine) the ‘ought’, say, by providing a better understanding of what humans are capable of – of what is possible.

Perhaps the ‘is’ shapes the “ought” regardless of our position on the is-ought problem. For instance, one may consider one’s moral values to be independent of “facts on the ground”, but upon closer examination it becomes clear that these values are steeped in assumptions about what ‘is’. Or one may explicitly believe that all questions of morality can be answered by sacred texts documenting the sayings of holy men. In this case, the “ought” is not the result of moral reflection but is wholly dependent on an “is”: because so-and-so said so.

It’s less common in modern secular society to rely on the “is” of sacred texts. Instead, people are more likely to draw ethical conclusions from what they consider to be natural facts. Appealing to nature to justify values, attitudes or behavior is often viewed by those on the opposite end of the is-ought divide as an example of the "naturalistic fallacy”. Some proponents of this “naturalist fallacy” claim that close attention to nature is all we need for moral guidance. Others propose that nature provides most of what we need to lead a moral life but allow that some highly abstract uber-values cannot be wholly derived from the natural world, such as the idea that the greatest happiness of the greatest number is the highest good.

So where do we stand on these issues? What is the relationship between the Is and the Ought? If we don’t derive our moral sense from observations of how the world works, how do we arrive at notions of right and wrong? Is there any connection between what we know about the natural world and how we ought to conduct ourselves as moral beings?

Is-Ought Problem Links:

http://en.wikipedia.o...
http://plato.stanford...
http://www.epjournal....
http://www.epjournal....
http://faculty.platts...

Also: A Treatise of Human Nature by David Hume: Book 3, Part 1, Section I
http://oll.libertyfun...