At the commencement of a campaign, to _advance_ or _not to advance_,
is a matter for grave consideration; but when once the offensive has
been assumed, it must be sustained to the last extremity. However
skilful the manœuvres in a retreat, it will always weaken the _morale_
of an army, because, in losing the chances of success, these last are
transferred to the enemy. Besides, retreats always cost more men and
_materiel_ than the most bloody engagements; with this difference, that
in a battle the enemy’s loss is nearly equal to your own--whereas in a
retreat the loss is on your side only.