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.

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.

People formerly seemed unable to evaluate a woman's c.v. or to accept a range of personal and communicative styles from the exuberant and confident to the sober and pedantic. It's much better than it was, and a number of male philosophers have been extraordinarily helpful in detecting and criticising everyday sexism in the profession.

Highly unequal societies are morally defective because they get to be that way through the exploitation by the clever and well-positioned ones of the vulnerabilities and weaknesses of others. The well-off then use their acquired political power to refuse to make sacrifices for others. This system brings us a wonderful range of products and experiences for consumers at the top of the privilege scale, but it also degrades and benumbs the workers at the lower end, as Adam Smith and Marx both said.

I had the idea that there were secret laws of the universe that could explain the baffling human reality around me, and that philosophers maybe had the key to them.

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.

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.