Objective Morals (aka Moral Realism)

Background

A friend and I were discussing objective morals. I thought all his claims and ideas were wrong. Of course, I liked my ideas. That lead me to look into the topic more. I looked up the leading logical arguments for moral realism, and I didn't find them very compelling compared to the arguments against moral realism.

Introduction

This is going to be a brainstorming post. I want to explain my ideas, thinking, and ask questions to guide the next phase of my inquiry.

My Biases

I don't believe in any creator, god, or religion. So the arguments built on a creator or attributes of a god are rejected because I reject the existence of those ideas. With that said, moral realism is not contingent on deism.

Evolution is one of the strongest theories in biology, if not all of science.

I believe in objective reality. Physical structures are undeniable. Ideologies and other abstract ideas are very much open for debate.

Epistemology wise, I'm a skeptic who leans heavily on 1) empiricism for knowledge that can be measured and 2) rationalism for knowledge that cannot be measured.

Logic is the best system of thinking.

The scientific method is the best system for understanding processes.

Questions (and how do we know?)

Are all, most, some, or few behaviors moral truths?

How many people have to agree for something to be a moral truth?

If people cannot agree, how do people decide what the moral truths are?

If there are moral truths, how can people know what they are? 

How do non human animals fit into the discussion?

How do psychopaths and or other sociopaths fit into the discussion?

How does the history of slavery and the abolishment of slavery prove/disprove moral realism?

How do laws prove/disprove moral realism?

If something like, do not murder, is a moral truth, how do we explain why people murder?

Even if everyone agrees murder is morally wrong, how do we know that's an objective truth and not culture?

For deist, what does it mean when a religion's god commands someone to break a moral truth?

If x is claimed to be a moral truth, does one situation where x is moral disprove x as a moral truth? 

My Priors

People do not agree.

The disagreement seems undeniable. I know that disagreement doesn't necessarily rule out moral realism, but it makes it obvious to me that people aren't going to agree. If we cannot agree, then how can we know which, if any, moral truths are true?

Let's look at killing.

A jainist might say killing a tree or plant is morally wrong. The US legal system might say killing is allowed in self defense. An army might say killing is allowed to protect and or conquer an area. Most people eat meat, so they think it is moral to kill animals for food. Hunters might hunt for sport. Many vegans stop eating meat because they decide it's morally wrong that animals have to suffer in factory farming conditions. And the list goes on. People have varying morals about killing. Maybe a moral realist would agree that killing isn't one of the moral truths.

It feels like I only need to find one black swan. Maybe this is a logical fallacy. But if a moral realist says x is a moral truth, I should only have to find one situation where x is moral.

What's Next?

Here are my next two stops. I'll add further resources as I find them. 

Moral Anti-Realism (Stanford Encyclopedia of Philosophy)

Moral Realism (Stanford Encyclopedia of Philosophy)