position, and on that account they have the same relations to the present subject.
The defensive consists, therefore, of two heterogeneous parts, the state of expectancy and that of action. By having referred the first to a definite subject, and therefore given it precedence of action, we have made it possible to connect the two into one whole. But an act of the defensive, especially a considerable one, such as a campaign or a whole war, does not, as regards time, consist of two great halves, the first the state of mere expectation, the second entirely of a state of action; it is a state of alternation between the two, in which the state of expectation can be traced through the whole act of the defensive like a continuous thread.
We give to this state of expectation so much importance simply because it is demanded by the nature of the thing. In preceding theories of war it has certainly never been brought forward as an independent conception, but in reality it has always served as a guide, although often unobserved. It is such a fundamental part of the whole act of war, that the one without the other appears almost impossible; and we shall therefore often have occasion to recur to it hereafter by calling attention to its effects in the dynamic action of the powers called into play.
For the present we shall employ ourselves in explaining how the principle of the state of expectation runs through the act of defence, and what are the successive stages in the defence itself which have their origin in this state.
In order to establish our ideas on subjects of a more simple kind, we shall defer the defence of a country, a subject on which a very great diversity of political influences exercises a powerful effect, until we come to the Book on the Plan of War; and as on the other hand, the defensive act in a position or in a battle is matter of tactics, which only forms a starting point for strategic action as a whole , we shall take the defence of a theatre,