The natural mental processes (see page 19) are employed in all of the four steps. The processes, in each step, require modification to an extent dependent upon the factors to be evaluated. A form has been adopted for the application of the mental processes in the first step. This form, long known to the military profession as The outline of The Estimate of The Situation (see Appendix), sets forth in a logical manner and order the several considerations likely to influence the selection of correct military objectives in problems of wide, as well as of lesser, scope. The use of this form is conducive to uniformity of reasoning. It centers the attention upon essentials, in order to ensure that no material factor bearing on the solution of the problem is overlooked. It guides thought along a specific path and, through the influence of suggestion, deliberately increases the expenditure of mental effort. The procedure indicated in the form contributes to the Decision reached as a result of an Estimate of the Situation, only to the extent that it provides an outline for, and encouragement of, systematic analysis and reasoning. To prove successful in stimulating rather than stifling creative thought, flexibility is a characteristic of any form capable of application in such dissimilar circumstances as may be presented by the varying scope of military problems. The Estimate Form is such a flexible guide. If a commander, in solving a problem, feels the need of greater flexibility, he may, of course, modify or adapt the form to his particular needs. In so doing, however, he bears in mind that departure from orderly processes of reasoning, on which the form is based, tends, through possible neglect of fundamental considerations, to lead to the omission of essential features of the analysis. On the other hand, a rigid following of the form may frequently cause much repetition. This may be avoided, unless desired for emphasis or other appropriate reasons, by reference back to preceding portions of the estimate. It is also to be noted, however, that the Estimate Form is adapted to a progressive procedure. Very frequently the earlier consideration of some aspect of the problem can later be expanded both in scope and in proper detail by reason of additional information which has become available during the intervening stages of the procedure.