The chances and accidents that attend military expeditions require great circumspection; and it is possible to provide for all of them with precision, provided that a man gives his mind to the conduct of his plan of campaign. Now that fewer operations in war are carried out openly and by mere force, than by stratagem and the skillful use of opportunity, any one that chooses may readily learn from the history of the past. And again that operations depending on the choice of opportunity oftener fail than succeed is easily proved from experience. Nor can there be any doubt that the greater part of such failures are due to the folly or carelessness of the leaders. It is time therefore to inquire into the rules of this art of strategy. Such things as occur in campaigns without having been calculated upon in any way we must not speak of as operations, but as accidents or casualties. It is the conduct of a campaign in accordance with an exact plan that I am to set forth: omitting all such things as do not fall under a scientific rule, and have no fixed design.