[bumblebeard]

Most utilitarians turn out not to actually think that way in real-life situations so I wouldn't worry about it. Moral realism is tied to religion for a lot of people and so some non-religious folks just reject it out of hand, which I think is a mistake.

IMO, moral truth exists as much as scientific truth we just interact with/discover it differently. The Stanford Encyclopedia of Philosophy is a good place to start if the topic interests you:

https://plato.stanford.edu/entries/moral-realism/

https://plato.stanford.edu/entries/moral-anti-realism/

[nickpsecurity]

"Most utilitarians turn out not to actually think that way in real-life situations so I wouldn't worry about it."

I agree based on lots of personal experience with and research on people who talked utilitarian but acted different when the law's enforcers were focused on them. I fought with myself over this in many situations balancing the struggle between my own survival/well-being vs supporting principles. Takes discipline and sacrifice to practice utilitarianism. What it took me led me to be suspicious of people who preach it who spontaneously do what benefits them esp at others' expense even in small ways.

[blazespin]

Yeah, sure sounds like science to me: "It is worth noting that, while moral realists are united in their cognitivism and in their rejection of error theories, they disagree among themselves not only about which moral claims are actually true but about what it is about the world that makes those claims true. Moral realism is not a particular substantive moral view