During a discussion in the pub the other day my friend suggested that morality -
Philosophers have been debating this issue for about 2500 years. As things now stand, most academic philosophers deny, or are inclined to deny, that moral rightness and wrongness are purely subjective: in the recent PhilPapers survey, a majority of "target faculty" favored moral realism over moral anti-realism. But it's an area of robust philosophical debate. You might start by looking at the SEP entries on moral realism and moral anti-realism. They contain careful discussions and lots of references to further reading.