Even if you just want to make a simple clothing item for yourself or go for a long hike in the forest - something we imagine requires absolutely no resources - you have to go to the store and buy a lot of stuff, and probably use a car.

People's wants are not fixed; they generally want what others in their chosen comparison class appear to be enjoying and what advertising presents to them as attainable for them and as bringing happiness.

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.

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.

Moral claims aren't, as a class, truth-value apt or not.

The (atomic) soul is mortal, and the best life is the one with the least pain and the most pleasure.

For seventeenth-century astronomers, the Epicurean doctrine of multiple worlds separated by void space was seen to fit with the new Copernican system in which every star was a sun, and the universe was a vast place with no centre.