The Struggle to do Good

[The Grand Nudger]

I'm not sure why being an atheist matters?

Because if God doesn't exist, then there is no other ontological basis for objective moral values and duties.

The claim is untrue on it's face, but if it were true, then morality could not be objective.  It would be subjective.  The good and the bad based on the nature of a given subject, god.  

So, from your perspective, there shouldn't be objective moral values and duties. Yet, you seem to think there are. You even stated a moral principle that you think is objectively true. It's poorly formed, but we can still use it.

I'm a moral realist.  I think that moral statements purport to report facts, and insomuch as they get those facts right, would be true.  That's all that's required for objective moral value and duty.  

"X is objectively evil if it causes harm to human beings"

Since you're an atheist, what or who is the source of this principle?

There's no need to add "objectively" in front of a realist statement.  It's implicit.  Yes, I think that it's bad to harm. 

I've already explained the source of this principle.  It's going to be the same in any question.  Relevant facts of a matter x.  

That's not what you wrote though. You wrote that X cannot be objectively true if it was told to you by a person. You seem to be backpedaling from that remark now, but I'm glad you're learning. That's a good sign.

It can be objectively true that vanilla is my favorite flavor of icecream, which is subjective. 

If we ask a person "why do you believe things" and they respond "because steve told me so",  then the statement x is bad does not refer to any relevant fact of x, but a fact of whether or not steve said something.  A fact of the subject.

So by watching people get harmed and being harmed yourself that somehow makes "harming human beings is objectively evil" true? That's just a non-sequitur. And there are people who derive entertainment and pleasure from watching people getting hurt. Does that mean "deriving pleasure from watching people getting hurt is objectively good," is true?

I think that human beings are moral agents capable of observing relevant facts.  

You're leveraging another subjectivist objection, btw, lol. There are certainly people who derive pleasure from doing bad things - that won't make them any less bad. There are people who would disagree that harm is bad, and that only makes them wrong. People disagree all the time, that doesn't mean that there isn't a right answer.