moral progress
... that a classic example of moral progress is the abolition of slavery?
... that a classic example of <b id="mwAS4"><a href="./Moral_progress" id="mwAS8" rel="mw:WikiLink" title="Moral progress">moral progress</a></b> is the <a href="./Abolitionism" id="mwATA" rel="mw:WikiLink" title="Abolitionism">abolition of slavery</a>?