But it was left for Seidlitz to perfect it under the direction of Frederick the Great.
Marshal Saxe very justly remarked, that cavalry is the "_arme du moment,_" for in almost every battle there are moments when a decisive charge of cavalry will gain the victory, but if not made at the instant it may be too late.

The efficiency of cavalry depends upon the moral impression which it makes on the enemy, and is greater in proportion to the size of the mass, and the rapidity of its motion.

This last quality enables a commander to avail himself immediately of a decisive moment, when the enemy exposes a weak point, or when disorder appears in his ranks.

But this requires a bold and active spirit, which shrinks not from responsibility, and is able to avail itself with quickness and decision of every opportunity.

If it be remembered that it is essential that this _coup d'oeil_, so rare and so difficult to acquire, be accompanied by a courage and vigor of execution which nothing can shake, we shall not be astonished that history furnishes so few good cavalry generals, and that this arm so seldom does such execution as it did under Frederick and Napoleon, with Seidlitz and Murat as commanders.
The soldier gains great _velocity_ by the use of the horse in war; but in other respects he is the loser.