Every variety of topography has peculiar requirements for its attack and its defence; and situations even though but little different from each other, nevertheless must be treated according to their particular nature.
In order to acquire the habit of selecting at a glance the correct posts for an army and of making proper dispositions of the kindred corps with rapidity and precision, topography should be studied with great attention, for most frequently it happens that circumstances do not allow time to do these things with deliberation.
PRINCIPLE
Acting either offensively or defensively, one never should proceed in such a way as to allow the enemy the advantage of ground;
That is to say: Kindred corps never should be exposed to unopposed adverse radii of offence, when the effect of such exposure is the loss of kindred material, or of time much better to be employed, than in making a necessary and servile retreat from an untenable post.
On the contrary, every kindred topographical advantage should unhesitatingly be availed of; and particular attention continually should be paid to advancing the kindred corps to points offensive where they cannot be successfully attacked.
Pains always must be taken to select advantageous ground. Indifferent posts must never be occupied from sheer indolence or from over-confidence in the strength of the kindred, or the weakness of the adverse army.
Particularly must one beware of permitting the enemy to retain advantages in topography; always and at once he should be dislodged from posts whose continued occupation may facilitate his giving an unforeseen and often a fatal blow.