Are moral realists delusional?
John Locke and George Berkley both had perceptions of a world around them. The difference is that Locke thought his perceptions existed not only in his mind, but that they also corresponded to a real world outside of his mind; whereas, Berkley thought his perceptions existed only in his mind, and that there was no external world.
In the same way, moral realists and moral non-realists both percieve a difference between right and wrong. The difference between them is that moral realists think their perceptions correspond to the real world, whereas moral non-realists think their perceptions exist only in their minds, and that in reality, there is no difference between right and wrong.
If Berkley is right, then we're all perceiving a world around us that isn't really there. It seems to be there, but it's just an illusion. If the moral non-realists are right, then we're all perceiving a distinction between right and wrong that isn't really there. Some things seem right and others wrong, but that's just an illusion.
Of course it's possible that there is no external world. It's possible that it's all an illusion or a dream. It's possible that these perceptions are only in our minds. But be honest with yourself; does that seem reasonable to believe?
It's also possible that there is no real difference between right and wrong. It's possible that our perception is merely a social construction that exists only in our minds. Apparently, there's a lot of people who think that is quite reasonable to believe, but I want to tell you one reason why I think it is quite unreasonable to believe.
Sociopaths have no moral motions. They feel no moral incumbancy. Though they may be told that some things are right and others wrong, this is merely academic to them. Though they may assent to what they are told, their conscience tells them nothing. They perceive no difference between right and wrong.
If there really is no difference between right and wrong, then sociopaths are perceiving the world more accurately than the rest of us. While we look at the world and perceive a difference between right and wrong that isn't really there, sociopaths see the world as it truly is--completely devoid of any right or wrong. But we all think sociopaths are crazy. That's why we consider it a mental illness. Their minds aren't working right. If we consider sociopathy to be a mental illness, that shows that we think a correctly working mind is a mind that percieves a difference between right and wrong.
How odd would we be if we considered a correctly working mind to be a mind that perceives things that aren't really there, and an incorrectly working mind to be a mind that perceives things accurately? Everything would be backwards. Mentally healthy people would be people who suffer from delusion, and mentally ill people would be people who see things they way they really are.
But let's be honest with ourselves; that's just nuts. If a correctly working mind perceives something, then there really is something there to be perceived. That's what it means for the mind to be working correctly--it means it perceives things that are really there, and it doesn't perceive things that aren't there. If a correctly working mind perceives a difference between right and wrong, then the perception of morality is an accurate perception. That means there really is a difference between right and wrong. It's not just in our heads.