Looking for critiques of my position

Hi everyone,

I'm working on a personal project to iron out my moral system and was looking for some potential objections. What I have so far:

Many people pretend that morality is a fact of the world. Yet we cannot see it, cannot measure it, and have disagreed over fundamental problems for centuries. I seek to reject this notion of morality and instead portray it as a human construction that we control. I have no interest in engaging with this idea of objective morality, and I will assume you to have abandoned such a silly view of the world as well.

What is morality?

Simply put, morality is how we ought to behave. Unfortunately, the universe doesn't tell us.

How do we construct a moral system?

Ultimately, the choice is up to us. I propose we begin by imposing certain constraints on potential moral systems before we construct our own.

Constraint 1: The moral system must be convincing.

If nobody seeks to adopt this system, of what use is it?

Constraint 2: The moral system must allow disagreement over fundamental moral issues.

No system will be acceptable for everyone. While the vast majority of humans share certain values (living, freedom, etc), there will always be an individual that rejects it. Our moral system must not lose sight of its subjective nature.

Constraint 3: The moral system must be practically consistent.

Within the world we live/possible worlds we can realistically imagine, our moral system must produce consistently acceptance results. Of course, certain hypotheticals that change our world beyond recognition can produce contradictions, but this is of no issue. After all, we are constructing a practical moral system, not discovering a divinely perfect ideology.

Egoism

A moral system is most convincing if we can justify it to people as in their own self interest. Take this hypothetical for example.

A man is locked in a room lined with explosives. The explosives are counting down from 1 minute, and will blow up the room, killing the man. However, there is a button in the room that can disarm the bombs and guarantee the man's safety. The only catch - pushing the button kills 2 people. An altruist would likely argue the man should not press the button. I however, don't think we can say that so easily. How can you convince someone to let themselves die? What do they gain from it? You could argue that living with the pain of killing people is worth more than death. But again, you are convincing a person by explaining what should be in their self interest. Convincing someone to do something for themself will always be easier than convincing them it's for the greater good.

It is with this understanding that I reject all moral philosophies grounded in altruism. While these systems may produce intuitive, feel good answers to moral questions, they ultimately have no way to justify themselves to outside parties.

Building our moral system from self interest may immediately appear to have some serious fundamental flaws. Since we are using intuition to guide the creation of this moral system, let’s investigate some potential problems.