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.
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.