Charles XII, in the battle of Narva, we cannot well quote, for the Russians were at that time hardly to be regarded as Europeans, also the principal circumstances, even of the battle, are too little known.

Buonaparte had at Dresden 120,000 against 220,000, therefore not the double.

At Kollin, Frederick the Great did not succeed, with 30,000 against 50,000 Austrians, neither did Buonaparte in the desperate battle of Leipsic, where he was 160,000 strong, against 280,000.
From this we may infer, that it is very difficult in the present state of Europe, for the most talented General to gain a victory over an enemy double his strength.

Now if we see double numbers prove such a weight in the scale against the greatest Generals, we may be sure, that in ordinary cases, in small as well as great combats, an important superiority of numbers, but which need not be over two to one, will be sufficient to ensure the victory, however disadvantageous other circumstances may be.

Certainly, we may imagine a defile which even tenfold would not suffice to force, but in such a case it can be no question of a battle at all.
We think, therefore, that under our conditions, as well as in all similar ones, the superiority at the decisive point is a matter of capital importance, and that this subject, in the generality of cases, is decidedly the most important of all.