It is by being precipitate and hasty in making such conclusions, that men are deceived, for to judge rightly of things before they become clearly shown is most difficult. _To act on uncertainty is WRONG._ We do not know all the facts and a single iota of light later on may oblige us to condemn that which we previously have approved. * * * * * In the making of Grand Reconnaissance, one always must be wary of placing too much confidence in appearances and in first impressions. Especially must care be taken not to magnify the weaknesses of the hostile army, nor the efficacy of the kindred position. Also, one never should underrate: 1. The talents of the opposing commander; nor 2. The advantages possessed by the opposing army: (a) In numbers, (b) In organization, (c) In position, (d) In topography, (e) In time, (f) In mobility. It is a first essential, constantly to note the movements of the enemy, in order to detect his plans and the exact location of his corps. These things are the only reliable guides for determining the true course of procedure. It must be left to the enemy to show by his movements and the posts which he occupies, the measures he projects for the future, and until these are known, it is not proper to _ACT_. Hence: PRINCIPLE _All movements of Corps Offensive should be governed by the POSITION of the hostile army, and all movements of Corps Defensive should be governed by the MOVEMENTS of the hostile army._ As soon as the enemy begins a movement, his intentions become clear. It is then possible to make precise calculations. But be not hasty to build conclusions upon uncertain information and do not take any resolutions until certain what are the numbers, the position, the objectives, and the projects of the enemy. However interesting an undertaking may appear, one should not be seduced by it while ill-informed of the obstacles to be met and the possibility of not having sufficient force in the theatre of action. Chimerical schemes should be abandoned at their inception. Reason, instead of extravagancies of the fancy, always must be the guide. Men, most courageous, often undertake fearful difficulties, but impracticable things they leave to lunatics. In all situations, one must beware of venturing beyond his depth. It is wiser to keep within the limits which the knowledge we possess shall prescribe. Especially in crises, one must proceed most cautiously until sure information is acquired; for over-haste is exceedingly dangerous, when exact knowledge is lacking of the enemy’s numbers, position, and movements. PRINCIPLE _Situations always should be contemplated as they EXIST, never as they OUGHT to be, or, perhaps, MAY be._ In every important juncture, each step must be profoundly considered; as little as possible should be left to chance.