Epicurus was in favour of friendly sex but not of grand passions or marriage and children, viewing them as sources of trouble and vexation.

You can find many philosophy papers on the themes of 'love' and 'friendship,' most of which are cheerful and somewhat anodyne; you don't find many on the loss of friends, relatives, and lovers from death or alienation, though it happens all the time.

You can reasonably make the intellectual journey from thinking it's permissible to eat shrimp to thinking it's not permissible, or vice versa, whereas our slavery journey was uni-directional. We are as certain we are not going back to that old kind of slavery as we are that we aren't going back to the geocentric universe.

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.

It used to be that nobody would really argue with a woman, because what she thought (unless it was by way of providing helpful comments about one's own work) just didn't matter.

There is no single test or formula for producing moral progress anymore than there is for generating scientific truths. It is a process involving theoreticians, fact-gatherers, protestors, martyrs for the cause, authors of first- person narratives who change the way we see and evaluate the distribution of harms and benefits.

The higher the coefficient of inequality (Gini coefficient) in a society, the worse things tend to be for those at the bottom.