word hovers between the formation of fleets and their strategical distribution.  Similar looseness will embarrass the student at every turn.  At one time he will find the word used to express the antithesis of division or dispersal of force; at another, to express strategic deployment, which implies division to a greater or less extent.  He will find it used of the process of assembling a force, as well as of the state of a force when the process is complete.  The truth is that the term, which is one of the most common and most necessary in strategical discussion, has never acquired a very precise meaning, and this lack of precision is one of the commonest causes of conflicting opinion and questionable judgments.  No strategical term indeed calls more urgently for a clear determination of the ideas for which it stands.

  [11] Daveluy, L’Esprit de la Guerre Navale, vol. i, p. 27, note.

Military phraseology, from which the word is taken, employs “concentration” in three senses.  It is used for assembling the units of an army after they have been mobilised.  In this sense, concentration is mainly an administrative process; logically, it means the complement of the process of mobilisation, whereby the army realises its war organisation and becomes ready to take the field.  In a second sense it is used for the process of moving the army when formed, or in process of formation, to the localities from which operations can best begin.  This is a true strategical stage, and it culminates in what is known as strategic deployment.  Finally, it is used for the ultimate stage when the army so deployed is closed up upon a definite line of operations in immediate readiness for tactical deployment—­gathered up, that is, to deal a concentrated blow.

Well as this terminology appears to serve on land, where the processes tend to overlap, something more exact is required if we try to extend it to the sea.  Such extension magnifies the error at every step, and clear thinking becomes difficult.  Even if we set aside the first meaning, that is, the final stage of mobilisation, we have still to deal with the two others which, in a great measure, are mutually contradictory.  The essential distinction of strategic deployment, which contemplates dispersal with a view to a choice of combinations, is flexibility and free movement.  The characteristic of an army massed for a blow is rigidity and restricted mobility.  In the one sense of concentration we contemplate a disposal of force which will conceal our intention from the enemy and will permit us to adapt our movements to the plan of operations he develops.  In the other, strategic concealment is at an end.  We have made our choice, and are committed to a definite operation.  Clearly, then, if we would apply the principles of land concentration to naval warfare it is desirable to settle which of the two phases of an operation we mean by the term.