points with which he is more particularly concerned. It is more likely, on the contrary, that criticism would completely fail in its object if it degenerated into a mechanical application of theory. All positive results of theoretical inquiry, all principles, rules, and methods, are the more wanting in generality and positive truth the more they become positive doctrine. They exist to offer themselves for use as required, and it must always be left for judgment to decide whether they are suitable or not. Such results of theory must never be used in criticism as rules or norms for a standard, but in the same way as the person acting should use them, that is, merely as aids to judgment. If it is an acknowledged principle in tactics that in the usual order of battle cavalry should be placed behind infantry, not in line with it, still it would be folly on this account to condemn every deviation from this principle. Criticism must investigate the grounds of the deviation, and it is only in case these are insufficient that it has a right to appeal to principles laid down in theory. If it is further established in theory that a divided attack diminishes the probability of success, still it would be just as unreasonable, whenever there is a divided attack and an unsuccessful issue, to regard the latter as the result of the former, without further investigation into the connection between the two, as where a divided attack is successful to infer from it the fallacy of that theoretical principle. The spirit of investigation which belongs to criticism cannot allow either. Criticism therefore supports itself chiefly on the results of the analytical investigation of theory; what has been made out and determined by theory does not require to be demonstrated over again by criticism, and it is so determined by theory that criticism may find it ready demonstrated.
This office of criticism, of examining the effect produced by certain causes, and whether a means applied has answered its object, will be easy enough if cause and effect, means and end, are all near together.
If an Army is surprised, and therefore cannot make a regular and intelligent use of its powers and resources, then the effect of the surprise