The latter can only be learnt from the memoirs of the chief actor, or from his intimate friends; and in such things of this kind are often treated of in a very desultory manner, or purposely misrepresented. Criticism must, therefore, always forego much which was present in the minds of those whose acts are criticised.
On the other hand, it is much more difficult to leave out of sight that which criticism knows in excess. This is only easy as regards accidental circumstances, that is, circumstances which have been mixed up, but are in no way necessarily related. But it is very difficult, and, in fact, can never be completely done with regard to things really essential.
Let us take first, the result. If it has not proceeded from accidental circumstances, it is almost impossible that the knowledge of it should not have an effect on the judgment passed on events which have preceded it, for we see these things in the light of this result, and it is to a certain extent by it that we first become acquainted with them and appreciate them. Military history, with all its events, is a source of instruction for criticism itself, and it is only natural that criticism should throw that light on things which it has itself obtained from the consideration of the whole. If therefore it might wish in some cases to leave the result out