Given a certain piece of evidence, what should one believe? Given a certain moral proposition, should one think it is right or wrong?
What is the fundamental difference between these oughts? Something about the epistemic norm/standard seems more grounded, fleshed out, and reasoned as opposed to say moral standards. And yet, if Hume is correct in there being no way to get an ought from an is, is this intuition mistaken?
For example, suppose one comes across a crime scene. A person has been murdered. It has been found that John’s fingerprints were on the gun that killed him. It has also been found that there was a message history of John saying that he would kill the victim. His DNA has been found on the victim as well.
Now, given this, what should you believe? Even if one asserts an axiom that states the goal should be to believe what is true, what reasons could one have to show that I should now believe that John is the murderer? What “degree of probability” should one attach to this belief, if that applies here? Both of these questions seem unanswerable because of the is-ought problem.
Or to rephrase, how would one argue against someone who thinks there is not enough evidence to suggest John is the murderer? That person could, for example, say that one should believe in nothing unless one can’t doubt it. And since John being the murderer can be doubted, one shouldn’t believe it. It seems that there’s no way to argue against this without hinging upon oughts that can’t be justified through any “is” statements.
And yet, intuitively, believing that John is a murderer here seems more well reasoned and objective than a proposition like “lying is bad”. Does this imply that our intuitions are wrong and that our beliefs ultimately are a matter of faith rather than some well reasoned rational standard?