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.

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 the chemists, who wanted to manufacture new medicines and elixirs and transform base substances into noble ones, the notion that there was no metaphysical barrier to doing so - it was just a matter of getting the particles into new arrangements - was encouraging. That was the Baconian programme.

There's Hobbes, who understood in the 1640s that the sovereign is not an appointee of God, or even a figure of superior virtue and wisdom, but just a functional device whose role is to keep people from hurting and killing each other.

People should be able to develop their abilities and interests and have access to such goods as friendship, artistry, and nature and a political voice. It's possible to be poor and yet have all this, but in a polarized society, and one where culture and adventure have been thoroughly monetised, it is a lot more difficult.

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

Epicureanism did inspire libertine culture in isolated sects, but Epicurus himself rejected an ethics of sensory indulgence, and he would have disowned latter-day 'Epicureanism' as a fussy, expensive, unphilosophical approach to eating and drinking.