It need not be remarked that a battle is a physical impossibility while both sides adhere to the passive defensive; and experience proves that battles are rare in which both sides are committed to the active offensive, whether by preference or necessity. Mars-la-Tour (16th August 1870) was the only contest of this nature in the Franco-German War. Bazaine had to be on the offensive because he was ordered to get away towards Verdun; Alvensleben took it because it was the only means whereby he could hinder Bazaine from accomplishing his purpose. But for the most part one side in battle is on the offensive; the other on the defensive. The invader is habitually the offensive person, just for the reason that the native force commonly acts on the defensive; the latter is anxious to hinder further penetration into the bowels of its land; the former's desire is to effect that penetration. The defensive of the native army need not, however, be the passive defensive; indeed, unless the position be exceptionally strong that is according to present tenets to be avoided. When, always with an underlying purpose of defence, its chief resorts to the offensive for reasons that he regards as good, his strategy or his tactics as the case may be, are expressed by the term "defensive-offensive." It says a good deal for the peaceful predilections of the nations, that there has been no fairly balanced experience affording the material for decision as to the relative advantage of the offensive and the defensive under modern conditions. In 1866 the Prussians, opposing the needle-gun to the Austrian muzzle-loader, naturally utilised this pre-eminence by adopting uniformly the offensive and traditions of the Great Frederick doubtless seconded the needle-gun. After Sadowa controversy ran high as to the proper system of tactics when breech-loader should oppose breech-loader. A strong party maintained that "the defensive had now become so strong that true science lay in forcing the adversary to attack. Let him come on, and then one might fairly rely on victory." As Boguslawski observes--"This conception of tactics would paralyse the offensive, for how can an army advance if it has always to wait till an enemy attacks?" After much exercitation the Germans determined to adhere to the offensive. In the recent modest language of Baron von der Goltz: [Footnote: _The Nation in Arms_, by Lieutenant-Colonel Baron von der Goltz. (Allen.)] "Our modern German mode of battle aims at being entirely a final struggle, which we conceive of as being inseparable from an unsparing offensive. Temporising, waiting, and a calm defensive are very unsympathetic to our nature. Everything with us is action. Our strength lies in great decisions on the battlefield." Perhaps also the guileless Germans were quite alert to the fact that Marshal Niel had shattered the French army's tradition of the offensive, and gone counter to the French