Solipsism assumes the objective reality of the self.

That would fit though, wouldn’t it? Objective reality == exists independently of the self. Solipsism == only the self is a given. At the very least it’s opposite-ish. And if not, then I simply don’t have a better answer, but it wasn’t my question to begin with.

It seems that it builds towards your questions though, and we would be better off if we could come to some agreement on objective reality.

Although I understand it’s unlikely philosophers will ever agree on what reality is.