does the genius of the commander count for nothing? Does he really do no more than apply the rules? Or, in point of science, are there great generals as there are great surgeons, who, when the symptoms exhibited by two states of ill-health are identical to the outward eye, nevertheless feel, for some infinitesimal reason, founded perhaps on their experience, but interpreted afresh, that in one case they ought to do one thing, in another case another; that in one case it is better to operate, in another to wait?”