You defined objective ethics as something every rational thinking being could derive.

Actually, I didn't. I would be interested in AaronBenson's answers to the questions that follow.

That definitely requires proof. Have you got even a reason for speculating about it, any evidence for it?

Here, I was just suggesting a solution. I don't have much interest in the concept of 'human' ethics. (Like Jack, I would be very interested in what ethics are universal to all evolved, intelligent, social minds.)

... Yet I didn't suggest it randomly. My evidence for it is that whenever someone seems to have a different ethical system from my own, I can usually eventually relate to it by finding a common value.