Nelson, who was a thoughtful as well as a daring tactician, expressed reasons for attacking one flank rather than another, under differing conditions in which the fleets presented themselves; but, speaking generally, the rear was the better to attack, because the van could not, and cannot, come as soon to help the rear as the rear can the van. It has to turn round, to begin with; and, before turning round, its commander has to make up his mind, which few men do quickly, unless they have reached conclusions beforehand. All this means time. Besides, the assailant can more easily place himself in the way of such new movement of the van, than he can of the rear coming up on the line of advance it already has. Still, there are some reasons in favor of the van. Nelson in 1801 said that in case of encountering a Russian fleet he would attack the van; because injury to it would throw the enemy’s order into confusion, from which the Russians were not good enough maneuverers to recover. That is a special reason, not a general. It takes account of a particular circumstance, as a general on shore does of a particular locality. When Farragut passed the Mobile forts his van was thrown into confusion, and all know what a critical moment that was. It matters little what the incident is, if the confusion is produced. In the Battle of the Japan Sea the attack again was on a flank, and that the van. Whether this was due to previous purpose of the Japanese, or merely arose from the conditions as they presented themselves, I do not know; but its tendency certainly would be to cause confusion. I do not wish, however, to argue here a question of tactics. My subject is strategy, and I am using tactics simply to illustrate the predominance, everywhere, under all conditions and from the nature of things, of the one great principle of concentration; and that, too, in the specific method of so distributing your own force as to be superior to the enemy in one quarter, while in the other you hold him in check long enough to permit your main attack to reach its full result. That necessary time may be half an hour on a field of battle; in a campaign it may be days, weeks, perhaps more. ... In any frontier line, or any strategic front of operations, or any line of battle, offensive effort may, and therefore should, be concentrated in one part, not distributed along the whole. This possibility, and a convenient way of conceiving it, Jomini expresses in an aphorism which may be commended to memory, because it sums up one important consideration concerning any military disposition whatever; whether it be the strategic front of operations in a campaign, or a tactical order of battle, or a frontier. Every such situation, Jomini says, may be properly regarded as a line; and every line divides, logically and actually, into three parts,—the center, and the two extremes, or flanks.