Progress is seldom simple; it comes with costs and casualties, even challenges about whether a change represents an advance or a retreat.

making a retreat so as to advance better.

Sometimes advance is the best form of retreat.

Without challenges and change there can be no progress.

There was a time when researchers imagined that Plan B, or the morning-after pill, might become not an emergency form of contraception but a routine one; women would take it once a month to induce a period and never even know whether they had gotten pregnant.

All wars, even the noblest, bring a reckoning of means and ends.