d, that, therefore, the
change from one line and object to another can only be regarded as
a necessary evil--that a turning movement is only justified by a
superiority of numbers generally or by the advantage of our lines of
communication and retreat over those of the enemy--that flank positions
are only justifiable on similar grounds--that every attack becomes
weaker as it progresses.

THE INTRODUCTION OF THE AUTHOR

THAT the conception of the scientific does not consist alone, or
chiefly, in system, and its finished theoretical constructions, requires
nowadays no exposition. System in this treatise is not to be found on
the surface, and instead of a finished building of theory, there are
only materials.

The scientific form lies here in the endeavour to explore the nature of
military phenomena to show their affinity with the nature of the things
of which they are composed. Nowhere has the philosophical argument been
evaded, but where it runs out into too thin a thread the Author has
preferred to cut it short, and fall back upon the corresponding results
of experience; for in the same way as many plants only bear fruit when
they do not shoot too high, so in the practical arts the theoretical
leaves and flowers must not be made to sprout too far, but kept near to
experience, which is their proper soil.

Unquestionably it would be a mistake to try to discover from the
chemical ingredients of a grain of corn the form of the ear of corn
which it bears, as we have only to go to the field to see the ears ripe.
Investigation and observation, philosophy and experience, must neither
despise nor exclude one another; they mutually afford each other the
rights of citizenship. Consequently, the propositions of this book, with
their arch of inherent necessity, are supported either by experience or
by the conception of War itself as external points, so that they are not
without abutments.(*)

(*) That this is not the case in the works of many military
writers especially of those who have aimed at treating of
War itself in a scientific manner, is shown in many
instances, in which by their reasoning, the pro and contra
swallow each other up so effectually that there is no
vestige of the tails even which were left in the case of the
two lions.

It is, perhaps, not impossible to write a systematic theory of War full
of spirit and substance, but ours hitherto, have been very much the
rever