Where do rights come from?

[Kuciwalker]

Exactly

[flash9286]

Jesus, NO.

The prohibition of murder does not exist to save any one individual from murder. It exists to prevent the collapse of the group from cycles of revenge or from a destruction of trusts between the individual members. As such, there are times when the group may chose to allow a murder to happen - for example, say a parent were to shoot a known pederast and pedophile who was their neighbor but was not in any way threatening a child at the time. It would be plausible to say that a jury of peers would allow the person to get off with minimal punishment if any, if only because the group thought that that was an individual whom it was worth killing to make everyone else's lives better. They have made a moral judgement that ending the life of a "bad man" is a good thing. On the other hand, it is never a "good thing" to violate a right, and the assumption is that the system would punish violators of rights all the time, because if punishment became conditional, the whole foundation of the right is undermined.

Fine, just add another exception to the right to live then. You can equally apply your rationale for the prohibition of murder to the existence of a right to life with exceptions.

[David Floyd]

This is certainly a simplistic view, which I will admit right off. However, I feel that a right is something that is pretty much universal to everyone, in terms of what standard we consistently apply not to others, but to ourselves.

In other words, a right to life exists not because I say it's wrong to kill someone else, but because everyone on the planet (every sane person, anyway) would agree that it's wrong for me to kill them, unprovoked (which is the reason the right to self defense exists - no sane person believes that self defense violates their attacker's rights). A right to property/possessions exists not because I say it's wrong to steal, but because no sane person innately believes that it is permissible for someone else to take their property/possessions without permission. A right to myself - that is, liberty - exists not because I say slavery is wrong, but because no one on the planet thinks it's OK for someone else to enslave them.

The problem comes in when you attempt to define things like property, slavery, liberty, etc. That's beyond the scope of the question, and I won't attempt to define it at this point.

[GePap]

No. We have Alice and Bob, who subscribe to a moral theory that states everyone has a right to pee in the shower. For Alice, there are only two moral claims that follow from this theory: first, that it would be wrong for her to interfere with Bob peeing in the shower, and two, that it would be wrong for Bob to interfere with her peeing in the shower.

This is exactly the same as them instead subscribing to a moral theory that states "no one may interfere with another person peeing in the shower".

The question of the thread is how such a "moral theory" would come into existence, so what is the point of discussing behaviors after a moral theory has been "formed"?

No, but your most basic mistake is a consistent inability to read. I explicitly disavowed that I was making claims about the historical origin of the current prevailing moral opinion.

Again, the question of the thread is the basis for ANY moral opinions - so are you saying that in fact you have done nothing to answer the OP?