A second disputed point is Clausewitz's alleged preference, as a rule, for the Inner Line in strategy. But it is necessary to remember that that was only due to the conditions of his time, before railways and telegraphs, when it was difficult to communicate between columns acting on concentric lines. And he is not in any way wedded to the Inner Line, like Jomini, but _only_ when circumstances are favourable. He has many sentences from which we may infer that, had he lived in railway and telegraph days, his strategy, like Moltke's, his most distinguished pupil, would have aimed at envelopment as a rule. For to bring up troops rapidly by several railways necessitates a broad strategic front, and Clausewitz especially lays down rapidity as his second great principle, and says-- "If the concentration of the forces would occasion detours and loss of time, and the danger of advancing by separate lines is not too great, then the same may be justifiable on these grounds; for _to effect an unnecessary concentration of the forces_ would be contrary to the second principle we have laid down (_i.e._ 'to act as swiftly as possible')."[69] Also: "Such separation into several columns as is absolutely necessary must be made use of for the disposition of the tactical attack in the enveloping form, _for that form is natural to the attack, and must not be disregarded without good reason_."[70] Also: "_It is sufficient now if the concentration takes place during the action._" So that while the conditions of his time led Clausewitz to prefer close concentration and the Inner Line, like Napoleon, yet his reflections led him to propound the germ of the strategy of Moltke. Substitute for Clausewitz's close concentration this: "As close concentration, the combined movements regulated by telegraph, as is compatible with the utmost use of the railways and the greatest rapidity" (as he would certainly have said), and we arrive at Moltke's strategy. FRONTAL ATTACKS