Philosophy
The Paradox of Moral Disagreement and Moral Realism
Quick fact
Philosopher J.L. Mackie argued that the mere existence of deep moral disagreement—between cultures and even within a single person's own evolving moral views—is evidence that moral values are not objective features of the world, but projections of our own attitudes and desires.
Why this is interesting
People have disagreed about right and wrong for millennia—honor killings are defended in some places while condemned in others. If moral truths were simply true, wouldn't everyone eventually agree?