On War
Clausewitz (1827)


I look upon the first six books, of which a fair copy has now been made, as only a mass which is still in a manner without form, and which has yet to be again revised. In this revision the two kinds of War will be everywhere kept more distinctly in view, by which all ideas will acquire a clearer meaning, a more precise direction, and a closer application. The two kinds of War are, first, those in which the object is the overthrow of the enemy, whether it be that we aim at his destruction, politically, or merely at disarming him and forcing him to conclude peace on our terms; and next, those in which our object is merely to make some conquests on the frontiers of his country, either for the purpose of retaining them permanently, or of turning them to account as matter of exchange in the settlement of a peace. Transition from one kind to the other must certainly continue to exist, but the completely different nature of the tendencies of the two must everywhere appear, and must separate from each other things which are incompatible.

Besides establishing this real difference in Wars, another practically necessary point of view must at the same time be established, which is, that war is only A continuation of state policy by other means. This point of view being adhered to everywhere, will introduce much more unity into the consideration of the subject, and things will be more easily disentangled from each other. Although the chief application of this point of view does not commence until we get to the eighth book, still it must be completely developed in the first book, and also lend assistance throughout the revision of the first six books. Through such a revision the first six books will get rid of a good deal of dross, many rents and chasms will be closed up, and much that is of a general nature will be transformed into distinct conceptions and forms.

The seventh book — on attack — for the different chapters of which sketches are already made, is to be considered as a reflection of the sixth, and must be completed at once, according to the above-mentioned more distinct points of view, so that it will require no fresh revision, but rather may serve as a model in the revision of the first six books.

For the eighth book — on the Plan of a War, that is, of the organisation of a whole War in general — several chapters are designed, but they are not at all to be regarded as real materials, they are merely a track, roughly cleared, as it were, through the mass, in order by that means to ascertain the points of most importance. They have answered this object, and I propose, on finishing the seventh book, to proceed at once to the working out of the eighth, where the two points of view above mentioned will be chiefly affirmed, by which everything will be simplified, and at the same time have a spirit breathed into it. I hope in this book to iron out many creases in the heads of strategists and statesmen, and at least to show the object of action, and the real point to be considered in War.

Now, when I have brought my ideas clearly out by finishing this eighth book, and have properly established the leading features of War, it will be easier for me to carry the spirit of these ideas in to the first six books, and to make these same features show themselves everywhere. Therefore I shall defer till then the revision of the first six books.

Should the work be interrupted by my death, then what is found can only be called a mass of conceptions not brought into form; but as these are open to endless misconceptions, they will doubtless give rise to a number of crude criticisms: for in these things, every one thinks, when he takes up his pen, that whatever comes into his head is worth saying and printing, and quite as incontrovertible as that twice two make four. If such a one would take the pains, as I have done, to think over the subject, for years, and to compare his ideas with military history, he would certainly be a little more guarded in his criticism.

Still, notwithstanding this imperfect form, I believe that an impartial reader thirsting for truth and conviction will rightly appreciate in the first six books the fruits of several years’ reflection and a diligent study of War, and that, perhaps, he will find in them some leading ideas which may bring about a revolution in the theory of War.

Berlin, 10th July, 1827.