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

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.

We are now returning to the 18th century empirical approach with the new interest in the evolutionary basis of ethics, with 'experimental' moral philosophy and moral psychology. As a result, we understand better why moral formulas are experienced as ineluctable commands, even if there is no commander and even if the notion of an inescapable obligation is just superstition. So moral philosophy has made huge progress.

Moral theory develops from the divine command theory of medieval Christian philosophy, mixed up with a bit of ancient pagan virtue theory, to the purely secular moral sentiment and interpersonal reaction theories of Smith and Hume, to Kant's attempt to restore command theory but with something supersensible in the individual rather than God as the source of authority.

Even if the gods did exist, the Epicureans argued, they didn't care about us. Rather, everything comes from nature, and all that really exists are atoms and void, moving and congregating.

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

Epicurus recommends bread and cheese as the staple, and his emphasis is more on avoiding pain than on seeking pleasure, insofar as pleasure-seeking tends to be followed by painful after-effects.