We have to gamble, and sometimes lose as George Ainslie argues; this keeps the appetite for life sharp.

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

Morality has in the past made progress when we broadened the category of things we weren't permitted to harm (animals, 'infidels'); saw through some delusions and rationalisations about what harms are good for people themselves (prison punishment, hysterectomies for unhappy 1950s wives); and readjusted our for-the-good of others criteria so as to demand only reasonable sacrifices (ceasing to use children as handy chimney sweeps).

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.

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.

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.

We have to gamble, and sometimes lose as George Ainslie argues; this keeps the appetite for life sharp.