The life-world of human and animal experience, with colours, tastes, solid objects, is a perceptual effect of massed atoms.

We call 'Slavery is wrong' a moral truth because there is a specific history of theoretical investigation of a particular kind of slavery. We discussed it for centuries in metaphysical, economic, biological, and philosophical terms; we listened to all the arguments pro and con, we read all the testimonies of slaves and witnesses, and we decided. Though this 'we" is not everybody on earth, or even most people, who've never thought about slavery much.

I don't see how being a faster runner, or a better mathematician makes you 'deserve' access to a better life, or more influence on policy, in the absence of a social decision to play that game in the way it's proposed to be organised for some set of benefits.

There's nothing a priori good about equality. One person has three televisions, the other has two, so what?

Epicurus was not at all interested in what we would call the problems of mass society, and he thought civic politics was just trouble and to be avoided by the wise.

I have to say that some philosophers such as the late Bernard Williams, and I would include myself in this group, would say that tranquillity is overrated as the goal of life.

Claims like 'Slavery is wrong' are not fully common-sensical, so they must be at least partly theoretical.