belong to
examples properly speaking, the two following belong to historical
proofs.

Thirdly, a historical fact may be referred to particularly, in order to
support what one has advanced. This is in all cases sufficient, if we
have ONLY to prove the POSSIBILITY of a fact or effect.

Lastly, in the fourth place, from the circumstantial detail of a
historical event, and by collecting together several of them, we may
deduce some theory, which therefore has its true PROOF in this testimony
itself.

For the first of these purposes all that is generally required is a
cursory notice of the case, as it is only used partially. Historical
correctness is a secondary consideration; a case invented might also
serve the purpose as well, only historical ones are always to be
preferred, because they bring the idea which they illustrate nearer to
practical life.

The second use supposes a more circumstantial relation of events, but
historical authenticity is again of secondary importance, and in respect
to this point the same is to be said as in the first case.

For the third purpose the mere quotation of an undoubted fact is
generally sufficient. If it is asserted that fortified positions may
fulfil their object under certain conditions, it is only necessary to
mention the position of Bunzelwitz(*) in support of the assertion.

(*) Frederick the Great's celebrated entrenched camp in
1761.

But if, through the narrative of a case in history, an abstract truth
is to be demonstrated, then everything in the case bearing on the
demonstration must be analysed in the most searching and complete
manner; it must, to a certain extent, develop itself carefully before
the eyes of the reader. The less effectually this is done the weaker
will be the proof, and the more necessary it will be to supply the
demonstrative proof which is wanting in the single case by a number of
cases, because we have a right to suppose that the more minute details
which we are unable to give neutralise each other in their effects in a
certain number of cases.

If we want to show by example derived from experience that cavalry
are better placed behind than in a line with infantry; that it is very
hazardous without a decided preponderance of numbers to attempt an
enveloping movement, with widely separated columns, either on a field
of battle or in the theatre of war--that is, either tactically or
strategically--then in the first of these cases it wou